University of Florida Thesis Or Dissertation Formatting

SIDEROXYLON SECTION FRIGORICOLA (SAPOTACEAE): A CLADE ENDEMIC TO TEMPERATE NORTH AMERICA

PAUL THOMAS COROGIN

A DISSERTATION PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY

UNIVERSITY OF FLORIDA

2015

To Ananda Devi, my wife and soulmate, whose presence beside me gives me strength

ACKNOWLEDGMENTS

I thank the following herbaria for loans of specimens: A, AUA, FLAS, FNPS,

FSU, FTG, GA, GH, LSU, MISS, OKL, TENN, UNA, US, USCH, and USF. I thank the following people without whose help this study could not have succeeded: Kent Perkins of the University of Florida Herbarium (FLAS) for his generous assistance with processing specimen loans; Brett Jestrow of Fairchild Tropical Garden (FTG) and

Jennifer Stafford of the National Park Service herbarium (FNPS) for facilitating my examination of south Florida herbarium specimens; Jimi Sadle, Mark Whitten, Bob

Simons, Wendy Poag, Lisa Kruse, and Dee Mincey, for assisting with field work; Karen

Kelley, electron microscopy manager, and Kim Backer-Kelley, lab technician, of the

ICBR Electron Microscopy Core lab at the University of Florida, for their kindness and expertise, and Kurt Neubig for his guidance and insights with the molecular work. And I thank my supervisory committee: Drs. Norris Williams, Pamela Soltis, Nigel Smith, and my advisor, Dr. Walter S. Judd, who gives so generously of his time to inspire in his students something of his passion for scholarship and botanical field expertise. I have indeed studied and learned from one of the best there is.

TABLE OF CONTENTS

page

ACKNOWLEDGMENTS...... 4

LIST OF TABLES...... 7

LIST OF FIGURES ...... 8

ABSTRACT...... 11

CHAPTER

1 INTRODUCTION ...... 13

The Family Sapotaceae ...... 13 The Genus Sideroxylon ...... 16 Biogeography of Sapotaceae in Southeastern North America ...... 18 The Aims of This Study...... 22

2 GENERIC AND SECTIONAL DELIMITATIONS WITHIN SIDEROXYLON ...... 24

Relationships of North American and Tropical Species of Sideroxylon Based On ITS Sequences ...... 26 Materials and Methods ...... 26 Results and discussion ...... 29

3 PHYLOGENETIC RELATIONSHIPS WITHIN SIDEROXYLON SECTION FRIGORICOLA BASED UPON MORPHOLOGY AND cpDNA SEQUENCES ...... 35

Species and Subspecies Concepts ...... 36 Materials and Methods ...... 37 General Morphology ...... 37 Morphological Cladistic Analysis ...... 38 Chloroplast DNA Analysis ...... 39 Results and Discussion ...... 41 Morphological Cladistic Analysis ...... 41 Chloroplast DNA Analysis ...... 44 Combined ITS + cpDNA Datasets ...... 45 Comparison of Phylogenies ...... 46 Assessment of Phylogenetic Species ...... 48

4 ECOLOGY AND BIOGEOGRAPHY ...... 62

Historical Biogeography of the Genus Sideroxylon ...... 62 The North American Coastal Plain: A Hotspot of Endemic Biodiversity...... 63 Sideroxylon section Frigoricola: A Group of NACP Endemics ...... 65

Habitats and Distribution ...... 66 Eco-Geographical Differentiation of the Species ...... 76

5 TAXONOMY ...... 79

Key to Species of Sideroxylon sect. Frigoricola ...... 89 Key to the Subspecies of Sideroxylon lanuginosum...... 143 Key to the Subspecies of Sideroxylon reclinatum ...... 179

6 CONCLUSION ...... 244

LIST OF REFERENCES ...... 247

BIOGRAPHICAL SKETCH ...... 264

LIST OF TABLES

Table page

2-1 List of taxa, vouchers, and GenBank accession numbers...... 31

3-1 Characters used in the morphology-based phylogenetic analysis...... 50

3-2 Character values used in cladistic analysis ...... 52

3-3 Character totals for DNA regions and combined datasets ...... 53

3-4 Putative autapomorphies for species of Sideroxylon section Frigoricola...... 54

LIST OF FIGURES

Figure page

2-1 Strict consensus of 12 most parsimonious trees from analysis of ITS sequences ...... 32

2-2 Representative cladogram: one of 12 most parsimonious trees generated in analysis of ITS sequences...... 33

2-3 Best tree generated by maximum likelihood analysis of ITS sequences ...... 34

3-1 Single most parsimonious tree from morphological analysis ...... 55

3-2 Strict consensus of 20 most parsimonious trees from MP analysis of sequences from five cpDNA regions ...... 56

3-3 Representative cladogram: one of 20 most parsimonious trees generated in MP analysis of sequences from five cpDNA regions...... 57

3-4 Best tree generated by maximum likelihood analysis of sequences from five cpDNA regions ...... 58

3-5 Strict consensus of five most parsimonious trees from MP analysis of combined dataset of ITS plus five cpDNA regions ...... 59

3-6 Representative cladogram: one of five most parsimonious trees generated in MP analysis of combined dataset of ITS plus five cpDNA regions ...... 60

3-7 Best tree generated by maximum likelihood analysis of combined dataset of ITS plus five cpDNA regions ...... 61

4-1 Geographical ranges of the species of Sideroxylon section Frigoricola ...... 78

5-1 Distribution of Sideroxylon sect. Frigoricola...... 214

5-2 SEM images of abaxial leaf surface of four individuals of Sideroxylon lycioides ...... 215

5-3 Sideroxylon lycioides ...... 216

5-4 Distribution of Sideroxylon lycioides ...... 217

5-5 SEM images of abaxial leaf surface of two individuals of Sideroxylon thornei . 218

5-6 Sideroxylon thornei...... 219

5-7 Distribution of Sideroxylon thornei ...... 220

5-8 SEM images of abaxial leaf surface of Sideroxylon tenax ...... 221

5-9 Sideroxylon tenax ...... 222

5-10 Sideroxylon tenax, morphological examples typical of species of Sideroxylon sect. Frigoricola ...... 223

5-11 Sideroxylon tenax, flower, typical of species of Sideroxylon sect. Frigoricola .. 224

5-12 Distribution of Sideroxylon tenax ...... 225

5-13 Sideroxylon tenax complex ...... 226

5-14 SEM images of abaxial leaf surface of Sideroxylon alachuense ...... 227

5-15 Sideroxylon alachuense ...... 228

5-16 Distribution of Sideroxylon alachuense ...... 229

5-17 SEM images of abaxial leaf surface of six individuals of Sideroxylon lanuginosum, representing the three subspecies ...... 230

5-18 Sideroxylon lanuginosum ...... 231

5-19 Distribution of Sideroxylon lanuginosum ...... 232

5-20 Distribution of morphological variants of Sideroxylon lanuginosum, sensu Cronquist (1945)...... 233

5-21 SEM images of abaxial leaf surface of four different individuals of Sideroxylon reclinatum subsp. reclinatum ...... 234

5-22 SEM images of abaxial leaf surface of four different individuals of Sideroxylon reclinatum subsp. austrofloridense ...... 235

5-23 Distribution of Sideroxylon reclinatum...... 236

5-24 Sideroxylon reclinatum ...... 237

5-25 Distribution of Sideroxylon reclinatum subsp. austrofloridense and S. reclinatum subsp. reclinatum ...... 238

5-26 Sideroxylon rufohirtum and S. macrocarpum: SEM images of abaxial leaf surface ...... 239

5-27 Sideroxylon rufohirtum ...... 240

5-28 Distribution of Sideroxylon rufohirtum ...... 241

5-29 Sideroxylon macrocarpum ...... 242

5-30 Distribution of Sideroxylon macrocarpum ...... 243

Abstract of Dissertation Presented to the Graduate School of the University of Florida in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy

SIDEROXYLON SECTION FRIGORICOLA (SAPOTACEAE): A CLADE ENDEMIC TO TEMPERATE NORTH AMERICA

Paul T. Corogin

August 2015

Chair: Walter S. Judd Major: Botany

Sideroxylon section Frigoricola (Sapotaceae) comprises eight species of shrubs or small trees endemic to temperate North America. These eight species are

Sideroxylon alachuense, S. lanuginosum, S. lycioides, S. macrocarpum, S. reclinatum,

S. rufohirtum, S. tenax, and S. thornei. Morphologically, these taxa are distinguished from their tropical congeners by having a combination of fascicled leaves, conspicuously reticulate tertiary venation, short styles, small fruits, and a bipartite hilum scar. A molecular phylogenetic analysis including these eight species plus 17 selected tropical relatives was conducted using nuclear ITS sequence data. The results confirm the monophyly of the group, which is here given recognition at sectional rank.

Relationships within the group were investigated based on detailed observations of morphological characters, as well as molecular analysis of the nuclear ITS DNA region, and five chloroplast DNA regions. Morphology-based cladistic analysis yielded a well- resolved phylogeny of the group. Several subclades are evident within the group: the S. lycioides + S. thornei clade, the S. tenax clade (i.e., S. tenax + S. alachuense), the S. lanuginosum clade (i.e., S. lanuginosum subspp. lanuginosum, rigidum, and albicans), the S. reclinatum clade (i.e., S. reclinatum subspp. reclinatum and austrofloridense),

and the S. rufohirtum + S. macrocarpum clade. The S. reclinatum clade plus the S. rufohirtum + S. macrocarpum clade form a clade, i.e., the S. reclinatum complex. DNA analysis suggested alternative groupings, but sequence divergence is minimal for the regions compared. Species of Sideroxylon section Frigoricola are endemic to an area encompassing much of the southeastern United States and the northern tier of states in

Mexico, most of these species being concentrated on the North American Coastal Plain from Texas through the Carolinas, an area recently recognized as a global hotspot of biodiversity and endemism. Florida is the center of diversity for the group. Sideroxylon section Frigoricola represents a recent radiation whose species are morphologically distinct and apparently eco-geographically differentiated. A formal taxonomic revision of the section is presented.

CHAPTER 1 INTRODUCTION

Sideroxylon L. is a genus of broad distribution in the pantropical family

Sapotaceae. Currently the only accepted genus in the tribe Sideroxyleae (Swenson &

Anderberg 2005; Smedmark & Anderberg 2007; Gautier et al. 2013; Stride et al. 2014),

Sideroxylon comprises ca. 80 species, distributed mainly in arid to semi-arid habitats and seasonally dry tropical forests of the Americas, Africa, and East Asia, and also in moist evergreen forests of Madagascar and the Mascarene Islands (Aubreville 1964;

Govaerts et al. 2001; Pennington 1991). In the Neotropics, Sideroxylon has its center of diversity in Central America and the Caribbean, and the genus extends into temperate southeastern North America. The temperate North American species of Sideroxylon are the subject of this study.

The Family Sapotaceae

The Sapotaceae are distinguished from related families in the order Ericales by the presence of latex, indumentum of brownish unicellular T-shaped hairs, fasciculate inflorescences, and seed with a large hilum scar (Stevens 2001; Pennington 1991).

Sapotaceae make a large contribution to tropical plant biodiversity, forming a major floristic component of tropical lowland wet forests in America, Asia, Africa, and the

Pacific Islands (Gentry 1988; Pennington 1991, 2004). Gentry (1988) ranked

Sapotaceae among the “top ten” plant families which together account for 40% - 73% of all species found in tropical lowland forests worldwide. Sapotaceae have long been economically important to humans; most species bear a more or less edible fruit, and the family provides valuable timber as well as several oil and latex products (Ruehle

1951; Williams 1964; Inglett & May 1968; Morton & Voss 1987; Pennington 1991;

Heaton et al. 1999; Maranz & Wiesman 2003; Gonzalez-Soberanis & Casas 2004;

Khallouki et al. 2005; Smith et al. 2007).

Prior to the use of molecular sequence data and cladistic analysis, generic delimitation and infra-familial relationships in Sapotaceae were based on overall morphological similarity. The taxonomy of Sapotaceae has always been problematic, for two reasons. First, morphological characters that have been deemed taxonomically useful are relatively few, their interpretation is often subjective, and they can exhibit high levels of homoplasy (Swenson & Anderberg 2005; Swenson et al. 2008, 2008b).

Second, these characters exhibit polythetic variation; that is, no single character can define a genus, so a genus must be defined by a combination of characters, and some of these characters tend to overlap with other genera. Since the time of Linnaeus, this has led to numerous widely differing generic circumscriptions within the Sapotaceae

(e.g., A. deCandolle 1844; Bentham & Hooker 1876; Hartog 1878; Radlkofer 1888;

Engler 1890-1891; Pierre 1890-1891; Baillon 1891; Dubard 1912, 1915; Lam 1925,

1938, 1939). This has given rise to a copious and confusing synonymy, with some species now having up to ten generic synonyms (Pennington 1990, 1991). Culminating this confusion were the publications of two discordant monographs of the family, one by

Aubreville (1964), recognizing 125 genera, and another by Baehni (1965), recognizing only 63 genera. In an effort to clarify this muddled state of affairs, Pennington (1990) published a monograph of Neotropical Sapotaceae, followed (1991) by his worldwide revision of the family. For the Neotropical monograph, he drew on previous works such as Miquel’s treatment in Martius’ Flora Brasiliensis (1863), more recent works by Ducke

(1942, 1953, 1957) on Brazilian Sapotaceae, and Aubreville’s The Botany of the

Guayana Highland (1972). Pennington’s worldwide monograph (1991) drew upon extensive field work, examination of herbarium specimens, pollen morphology and secondary chemistry studies, and the work of previous taxonomists, and redefined the genera and their relationships. Although Pennington did not employ phylogenetic methods, his system, recognizing 53 genera in five tribes, is still highly regarded as a definitive work on the Sapotaceae.

More recently, however, phylogenetic studies have shown that it is necessary to modify Pennington’s classification, as some of his genera and tribes are found to be non-monophyletic. Two studies using morphology and chloroplast DNA sequences

(Anderberg and Swenson 2003; Swenson and Anderberg 2005) divide the family into three monophyletic subfamilies: the Sarcospermatoideae, which includes the genus

Sarcosperma, now recognized as sister to all remaining Sapotaceae; the Sapotoideae, containing all species corresponding to Pennington’s tribes Isonandreae, Mimusopeae, and Sideroxyleae; and the Chrysophylloideae, encompassing the species corresponding to Pennington’s tribes Chrysophylleae and Omphalocarpeae. The

Sapotoideae includes two tribes, Sapoteae and Sideroxyleae (Swenson and Anderberg

2005). Pennington (1991) had lumped many previously recognized genera into larger, more broadly defined groups, but some of these large genera, such as Chrysophyllum and Pouteria, are proving to be polyphyletic, and therefore should be split to reflect monophyletic lineages (Swenson and Anderberg 2005). In some cases, these newly segregated genera correspond to genera Pennington had submerged by lumping them into larger groups. For example, phylogenetic studies focusing on the Sapotaceae in the

Australasia - New Caledonia region (Bartish et al. 2005, Swenson et al. 2007, 2008a),

show that several previously recognized genera are actually monophyletic, and can therefore be re-separated from large genera such as Pouteria, from which the authors propose resurrecting Beccariella, Planchonella, Sersalisia and Van-royena (Swenson et al. 2007).

The Genus Sideroxylon

The species of Sideroxylon are trees and shrubs of mainly dry habitats, armed with thorns or unarmed, with leaves alternate to subopposite, often becoming fascicled on short shoots (brachyblasts), inflorescences fasciculate, axillary or in axils of fallen leaves, flowers with a single whorl of quincuncial sepals, corolla lobes entire or often divided into a median segment and two lateral segments, petaloid staminodes alternating with epipetalous stamens, seeds with thin cotyledons and copious endosperm, or with fleshy cotyledons and endosperm scanty or lacking, the hilum scar unipartite or bipartite and in a basal position (Pennington 1991).

Prior to Pennington’s monographs of the Sapotaceae (1990, 1991), the species of the current genus Sideroxylon were split among several genera. The Neotropical species of Sideroxylon were split among the genera Bumelia Sw., Dipholis A.DC., and

Mastichodendron (Engl.) H.J. Lam. The species endemic to the continental United

States (and extreme northern Mexico), along with many tropical taxa (Cronquist 1945,

1946, 1949), were treated under the genus Bumelia for two centuries following the segregation of Bumelia from Sideroxylon by Swartz (1788). During this time, Bumelia was revised by Gray (1886), Small (1900), Clark (1942), and Cronquist (1945, 1949).

Pennington (1991), circumscribing genera based on discontinuities in the pattern of variation of sets of characters, found no sound morphological basis upon which to recognize these genera, and he transferred all of Bumelia, Dipholis, and

Mastichodendron into a broadly circumscribed Sideroxylon. For species limits he generally followed Cronquist. More recently, phylogenetic analyses using both morphological and molecular data have shown that Sideroxylon sensu Pennington is monophyletic if Argania, from Morocco, is included (Anderberg & Swenson 2003;

Swenson & Anderberg 2005; Smedmark et al. 2006), and if Sideroxylon oxyacanthum, from the Arabian peninsula, and S. discolor, from Socotra, are excluded (Smedmark &

Anderberg 2007; Gautier et al. 2013; Stride et al. 2014). Two of these molecular phylogenies show that species formerly treated under the genus Bumelia form a well- supported clade within Sideroxylon (Smedmark & Anderberg 2007; Stride et al. 2014).

Although Bumelia is difficult to diagnose morphologically, further study of relationships within Sideroxylon with more thorough taxon sampling could allow recognition of

Bumelia as a subgenus.

Although it is primarily a tropical genus, eleven species of Sideroxylon are currently recognized in the continental United States (Govaerts et al. 2001; Allison

2006; Wunderlin & Hansen 2008). Of these eleven species, eight are endemic to an area encompassing much of the southeastern United States and the northern tier of states in Mexico, most of these species being concentrated on the coastal plain from

Texas through the Carolinas, with Florida as their center of diversity (Govaerts et al.

2001; Allison 2006; Wunderlin & Hansen 2008). These eight species are Sideroxylon alachuense L.C. Anderson, S. lanuginosum Michx., S. lycioides L., S. macrocarpum

(Nutt.) J.R. Allison, S. reclinatum Michx., S. rufohirtum Herring & Judd, S. tenax L., and

S. thornei (Cronquist) T.D. Penn. Morphologically, these taxa can be distinguished from their tropical congeners by having a combination of fascicled leaves, conspicuously

reticulate tertiary venation, short styles, small fruits, and seeds with a bipartite hilum scar (Pennington 1990). These possibly synapomorphic morphological features, along with results of recent molecular phylogenetic analyses (Smedmark & Anderberg 2007;

Stride et al. 2014), suggest that these species likely form a monophyletic group. The monophyly of this group, and the relationships among its member taxa, are considered in the following chapters of the present taxonomic study.

Biogeography of Sapotaceae in Southeastern North America

From the fossil record and molecular dating techniques, it appears that the flowering plants were beginning to appear in the late Jurassic period, ca. 167 million years ago (167 Ma); by the mid-Cretaceous period (125 Ma), many major lineages can be recognized, and by the late Cretaceous, flowering plant diversification was extensive, and they were becoming dominant in the world’s flora (Judd et al. 2007; Bell et al.

2010). During this span of time, the breakup of supercontinents Pangaea and

Gondwana was ongoing, but the land masses were still positioned close together, allowing for dispersal of major flowering plant lineages to every continent early in their evolution (Lomolino et al. 2006). The age of the Sapotaceae has been estimated at approximately 80–100 million years (Bremer et al. 2004; Bell et al 2010; Richardson et al. 2014). But the earliest fossil record of Sapotaceae is pollen from the early Eocene

(ca. 55 Ma), by which time this fossil Sapotaceous pollen is found on all continents and exhibits similarities to all major modern groups within Sapotaceae (Harley 1991).

Molecular dating estimates for the tribe Sideroxyleae suggest that Sideroxylon began to diversify between 62 and 50 Ma (Smedmark & Anderberg 2007; Stride et al. 2014), a time when global climate was much warmer than today, allowing the development of a

Boreotropical flora across much of the Northern Hemisphere (Wolfe 1975; Tiffney 1985;

Morley 2000). Smedmark and Anderberg (2007) hypothesized that Sideroxylon originated in Africa and arrived at its current pantropical distribution via the North

American Land Bridge ca. 55 Ma during the Late Paleocene-Early Eocene climatic maximum, which allowed the Boreotropical flora to spread beyond 50°N latitude, with ranges of tropical species contracting to their current limits as global climate subsequently cooled in the Oligocene (Tiffney 1985; Morley 2000). But Stride et al.

(2014) argue there is evidence to support a Neotropical origin for Sideroxylon and subsequent long-distance dispersal to its current distribution. In any case, the molecular dating estimate of Stride et al. (2014) indicates that a clade of Sideroxylon extended its range into southeastern North America sometime between 42 and 2.8 Ma, perhaps giving rise to the group of taxa currently occurring there.

The flora of southeastern North America is biogeographically interesting. Over more than 50 million years of fluctuating global climate and sea levels, this area, stretching from the mid-Atlantic states westward across the southern Appalachians to coastal east Texas and northern Mexico, has had conditions ranging from subtropical to cool temperate, wet to dry, but never glaciated. During glacial maxima of the ice ages, this area provided refugia for northern taxa and experienced compressed zones of vegetation types that created unique associations of species reflected in areas of high endemism seen today (Soltis et al. 2006). Several such centers of endemism have been identified in southeastern North America, most of which fall within the North American

Coastal Plain (NACP), a large natural physiographic region extending from southern

New England southward through eastern Virginia and the Carolinas, southern Georgia, all of Florida, west to eastern Texas, and south into Tamaulipas, Mexico (Estill & Cruzan

2001; Sorrie & Weakley 2001, 2006; Noss et al. 2015). As defined by Sorrie and

Weakley (2001), the coastal plain represents the exposed portion of the continental shelf, and includes also the Mississippi Embayment, where the plain extends up the

Mississippi valley to southern Illinois and southeastern Missouri. The physiographic outlines of the NACP define the Coastal Plain Floristic Province, whose flora, in some places, is geologically relatively young due to repeated Pleistocene inundations, but has received inputs from older floras in the Appalachians, the Caribbean, western North

America, and parts of the coastal plain that escaped inundation (Webb 1990; Thorne

1993; Sorrie and Weakley 2001, 2006). Some parts of the NACP were never inundated, and have been climatically stable and continuously vegetated since the Late

Cretaceous, ca. 80-85 Ma (DiPietro 2013; Noss et al. 2015). During numerous high sea level incursions, these areas of higher ground served as refugia for relict taxa and were sometimes isolated from each other, allowing for allopatric speciation and promoting a high degree of endemism (Noss et al. 2015). Moreover, although much of the NACP appears topographically flat and homogeneous, there is in fact a rich patchwork of differing habitats and vegetation types resulting from subtle elevation changes, different soil types, and a predominance of pyrogenic associations maintained by lightning- caused fires, all contributing to high biodiversity and endemism (Platt & Schwartz 1990;

panhandle, especially the Apalachicola Bluffs (Ward 1979). Due to its unique scrub habitat, the degree of endemism on Florida’s Lake Wales Ridge is high by continental standards, exceeded only by islands such as Hawaii (Christman and Judd 1990; Stein et al. 2000; Zona & Judd 1986). Although the NACP has long been understood as an area of high biodiversity and endemism, it has gone unrecognized in recent designations of global biodiversity hotspots (e.g., Myers et al. 2000; Mittermeier et al.

2011). Noss et al. (2015) have given the NACP well-deserved formal designation as a hotspot, pointing out that additional unrecognized hotspots undoubtedly exist around the world. The North American Coastal Plain is thus of great interest to botanists for the evolutionary history of its flora and as a center of endemic biodiversity.

The many narrow endemic taxa of these areas have been of interest to taxonomists, not only for the intrinsic appeal of their rarity, but also because understanding the taxonomic relationships among such plants can help us understand patterns of speciation and biogeographic affinities. Some of these endemics have been well studied; for example, mints in the genera Dicerandra (Huck et al. 1989; Oliveira et al. 2007) and Conradina (Edwards et al. 2006, 2009), grasses in the Andropogon virginicus complex (Campbell 1983), pawpaws in the genus Asimina (Neubig & Abbott

2010; Chatrou et al. 2012), pitcher plants in the genus Sarracenia (Ellison et al. 2014), and species in the genera Hypericum (Adams 1962), Trillium (Freeman 1975),

Polygonella (Nesom & Bates 1984); Rhododendron (Kron 1993), Iris (Meerow et al.

2005), and Rhexia (Ionta et al. 2007). But other groups of endemic taxa are in need of study. One such group is the clade of Sideroxylon that is endemic to southeastern North

America, the subject of the present monograph. This clade includes a number of narrow

endemics; i.e., taxa with very restricted distributions. The distributions of some of these taxa correspond with Florida’s three hotspots of endemism as discussed above. One taxon, S. reclinatum subsp. austrofloridense, is found only in the pine rocklands of the

Everglades (Whetstone 1985). Another, S. thornei, is restricted to a few counties in southwest Georgia and the Florida panhandle (Cronquist 1949, GDNR 2009). Still another, a morphologically distinct variant of S. tenax, once recognized as Bumelia lacuum (Small 1933, Lakela 1963), occurs only on the Lake Wales Ridge and adjacent sand ridges in the central Florida peninsula. Other narrow endemics have distributions not corresponding to these three hotspots, but nevertheless they are located within areas of coastal plain endemism identified by researchers (e.g., Estill & Cruzan 2001;

Sorrie and Weakley 2001). Sideroxylon alachuense occurs in only a few scattered populations in Alachua, Marion, Lake and Orange counties in north central Florida

(Sargent 1921, Anderson 1997, Wunderlin & Hansen 2008). Sideroxylon macrocarpum is restricted to a few populations in southeastern Georgia (Allison 2006, GDNR 2009), and S. rufohirtum is found only in a few counties in the northern and western Florida peninsula (Herring & Judd 1995). Three of these taxa (S. alachuense, S. lycioides, and

S. thornei) are listed as endangered by the State of Florida, and two taxa (S. macrocarpum and S. thornei) are listed as rare by the State of Georgia (Wunderlin and

Hansen 2008; GDNR 2009). These taxa occur in an array of soil types, habitats, and hydrological conditions, some taxa being separated from others by strict habitat preference, suggesting that these taxa have diversified ecologically.

The Aims of This Study

The presence of so many narrow endemic and rare taxa in southeastern North

American Sideroxylon makes this a group of special interest. Why certain clades

contain an unusually high number of narrow endemics is still not well understood.

Central to any inquiry into the causes and consequences of narrow endemism is the study of the evolutionary history and biogeography of such a clade, beginning by generating a phylogeny of its species (Oliveira et al. 2007). Systematic studies make a valuable contribution to conservation biology (Soltis & Gitzendanner 1999). An elucidation of the relationships among the North American species of Sideroxylon will clarify taxonomic designations, providing information for use by conservation decision makers. Along with a phylogeny, analysis of molecular sequences in this group will help answer biogeographical questions. The aim of the present study is to address these issues by adding to our biological understanding of this group of plants.

In Chapter 2, I present the results of a phylogenetic analysis of the Sideroxylon taxa that are endemic to southeastern North America, based on nuclear ITS DNA sequences. The aim is to test the monophyly of the group, to assess its species composition, and to determine its taxonomic placement within the genus. In Chapter 3, I present the results of phylogenetic analyses based on morphology and on chloroplast

DNA sequence data, generating hypothesized phylogenies of the group. In Chapter 4, the ecology and biogeography of the group is discussed in detail. Chapter 5 is a formal taxonomic revision of the species and subspecies in the group.

CHAPTER 2 GENERIC AND SECTIONAL DELIMITATIONS WITHIN SIDEROXYLON

Prior to Pennington’s monographs of the Sapotaceae (1990, 1991), the species of Sideroxylon as currently circumscribed were split among several genera. Sideroxylon sensu stricto contained species from Africa and the Mascarene Islands. The Neotropical species of Sideroxylon, centered in the Caribbean and Central America and extending into the temperate southeastern United States, were divided among the genera Bumelia

Sw. (corolla lobes divided, seed without endosperm), Dipholis A.DC. (corolla lobes divided, seed endospermous), and Mastichodendron (Engl.) H.J. Lam (corolla lobes entire, seed endospermous). The species endemic to the continental U.S. (and extreme northern Mexico) were assigned to Bumelia, along with many tropical taxa (Gray 1886,

Small 1900, Clark 1942, Cronquist 1945, 1946, 1949). However, generic delimitation within the Sapotaceae has always been difficult because characters used to define genera often exhibit polythetic variation; i.e., no single character can define a group, so genera must be based on suites of characters. Pennington, in his revision of

Sapotaceae (1991), circumscribed genera based on discontinuities in the pattern of variation of sets of characters. Using this approach, Pennington (1990, 1991) found no sound morphological basis on which to recognize these genera, and he transferred all of Bumelia, Dipholis, and Mastichodendron into a broadly circumscribed Sideroxylon.

For species limits he generally followed Cronquist. More recently, phylogenetic analyses using both morphological and molecular data have shown that Sideroxylon sensu

Pennington is monophyletic if Argania from Morocco is included (Anderberg & Swenson

2003; Swenson & Anderberg 2005; Smedmark et al. 2006), and if Sideroxylon

oxyacanthum from the Arabian peninsula and S. discolor from Socotra are excluded

(Smedmark & Anderberg 2007; Gautier et al. 2013; Stride et al. 2014).

Two recent molecular phylogenies sampling 28 Neotropical Sideroxylon species, using nuclear ITS and chloroplast DNA sequences (Smedmark & Anderberg 2007;

Stride et al. 2014), reveal subclades within Sideroxylon, among which the relationships are unclear. One subclade corresponds to Sideroxylon sensu stricto, containing many

Paleotropical species, and there are two well–supported Neotropical subclades, one corresponding to Dipholis/Mastichodendron, and the other to Bumelia. The Bumelia clade in these analyses (i.e., clade N, Figs. 1 and 2, Smedmark & Anderberg 2007; clade F, Fig.1, Stride et al. 2014) has high support, and includes four of the North

American species (i.e., Sideroxylon lycioides, S. tenax, S. lanuginosum, and S. reclinatum) along with 13 tropical species. These analyses show that the four North

American species form a well–supported clade within Bumelia that is sister to the remaining species in Bumelia (i.e., clade T, Figs. 1 and 2, Smedmark & Anderberg

2007; clade F1, Fig.1, Stride et al. 2014). These four species, along with four additional species (i.e., S. thornei, S. alachuense, S. rufohirtum, and S. macrocarpum), are endemic to the continental United States and the northern tier of states in Mexico. Do these eight species constitute a monophyletic group? Prior to this monograph, such a close relationship has been hypothesized based on a few possibly synapomorphic morphological features, i.e., leaves fascicled on brachyblasts on older stems, conspicuous tertiary venation, short styles, small fruit, and seeds with a bipartite hilum scar (Pennington 1990; see Chapter 5), but no phylogenetic analysis has included all eight of the species. To test the monophyly of this putative North American clade, and to

address the question of clade membership, a molecular phylogenetic analysis including all of these eight species plus 17 selected tropical relatives was conducted using ITS sequence data. In addition, a morphology–based cladistic analysis of the North

American species is presented in the following chapter.

Relationships of North American and Tropical Species of Sideroxylon Based On ITS Sequences

To test the monophyly of the North American clade mentioned above, and to ascertain which species comprise it, a phylogenetic analysis was performed based on internal transcribed spacer (ITS) regions of nuclear ribosomal DNA for the eight species putatively belonging in this clade, i.e., Sideroxylon lycioides, S. tenax (including both

Atlantic coast and inland Florida ridge populations), S. lanuginosum, S. reclinatum (both subspecies), S. thornei, S. alachuense, S. rufohirtum, and S. macrocarpum, along with

17 selected tropical relatives based on the analysis of Smedmark and Anderberg (2007;

Table 2-1). Of these 17 relatives, 12 are Neotropical congeners–six from the Bumelia clade, i.e., S. persimile, S. palmeri, S. celastrinum, S. americanum, S. horridum, and S. obtusifolium, and six from outside of the Bumelia clade, i.e., S. capiri, S. foetidissimum,

S. stevensonii, S. cubense, S. salicifolium (all from the Dipholis/Mastichodendron clade), and S. leucophyllum (of uncertain placement). Four are Paleotropical congeners, i.e., S. inerme, S. majus, S. saxorum, and Argania spinosa, the latter now transferred to

Sideroxylon (Stride et al. 2014).

Materials and Methods

ITS sequences for the tropical taxa selected for this analysis, based on

Smedmark and Anderberg (2007; listed above; Table 2-1), were downloaded from

GenBank to be used in the analysis along with ITS sequences from taxa from which

DNA was extracted and amplified as outlined below.

For the eight species in the North American clade plus Sideroxylon celastrinum

(Table 2-1), leaf material was taken from herbarium specimens: S. lycioides, S. macrocarpum, S. tenax (Atlantic coast), S. thornei, or collected fresh and dried in silica gel: S. alachuense, S. celastrinum, S. lanuginosum, S. reclinatum subsp. reclinatum, S. reclinatum subsp. austrofloridense, S. rufohirtum, S. tenax (inland Florida Ridge).

Voucher specimens of fresh–collected taxa used in this DNA analysis are deposited at

FLAS (Table 2-1). All of these taxa were sequenced for internal transcribed spacer regions of nuclear ribosomal DNA including portions of the 18S and 26S genes, and the entire ITS1, 5.8S cistron, and ITS2 regions. Total genomic DNA was extracted using a cetyl trimethylammonium bromide (CTAB) protocol modified from Doyle and Doyle

(1987). Approximately 10 mg of dried leaf tissue was ground with 1 ml CTAB 2 × buffer and 2 ml of Proteinase–K, (25 micrograms/mL; Promega, Inc.), then incubated at 65°C for 30–120 minutes. DNA was precipitated overnight with isopropanol at –20°C, centrifuged for 20 minutes at 13,000 rpm, washed twice with 70% ethanol, and dried.

The DNA pellet was then resuspended in 75 ml of 1X TE (Tris–EDTA buffer, pH 8.5) and incubated at 65°C for approximately 30 minutes. DNA quality was checked by electrophoresis. Preceding PCR amplification, total DNA samples were cleaned with

QIAquick columns (Qiagen, Inc., Santa Clarita, California, USA) following manufacturer’s instructions, to remove inhibitory secondary compounds. PCR amplifications were performed using an Eppendorf Mastercycler EP Gradient S thermocycler and Sigma brand reagents in 25–µL volumes with reaction components for

ITS: 1 µL of template DNA (approximately 10–100 ng), 11 µL of water, 6.5 µL of 5 M betaine, 2.5 µL of 10 × buffer, 3 µL of MgCl2 (25 mM), 0.5 µL of 10 mM dNTPs, 0.5 µL each of 10 µM primers and 0.5 units (0.2 µL) of Taq DNA polymerase.

ITS was amplified with a touchdown thermal cycling protocol using the parameters 94 °C for 2 min; 15 × (94 °C for 1 min; 76 °C for 1 min, reducing 1 °C per cycle; 72 °C for 1 min); 21 × (94 °C for 1 min; 59 °C for 1 min; 72 °C for 1 min); 72 °C for

3 min with the primers 17SE (F) and 26SE (R) sensu Sun et al. (1994). Betaine was added to eliminate secondary structure typical of the ribosomal DNA, so that active ITS copies would predominate in the PCR product. The PCR product was purified using

QIAquick columns and then checked again on an agarose gel for quality. PCR products were sequenced and analyzed at the DNA Sequencing Core Lab at the University of

Florida. Sequences were edited using Sequencher version 4.10.1 (Gene Codes, Ann

Arbor, Michigan). All sequences were deposited in GenBank (Table 2-1). These edited

ITS sequences, along with additional sequences downloaded from GenBank (as listed above), were manually aligned using SeaView version 4 (Galtier et al. 1996, Gouy et al.

2010).

Phylogenetic analyses were performed on these aligned ITS sequences using both parsimony and maximum likelihood (ML) optimality criteria. Sarcosperma laurinum, which has been shown to be sister to the remaining Sapotaceae (Swenson & Anderberg

2005), was used to root the trees. Analyses were conducted using PAUP* 4.0b10

(Swofford 2002). A parsimony analysis was conducted using the branch–and–bound algorithm with equally–weighted characters, gaps treated as missing, MAXTREES setting 200, MULTREES option in effect. Strength of support for clades revealed in the

analysis was assessed using bootstrap support (Felsenstein 1985). The bootstrap analysis (1000 replicates) was conducted using a heuristic search, with TBR branch swapping, 10 random additions per replicate. For the maximum likelihood analysis, a likelihood ratio test (Goldman 1993; Huelsenbeck & Crandall 1997) as implemented in

ModelTest 3.7 (Posada & Crandall 1998) was used to determine the maximum likelihood model that best fit the data set. Model parameter values generated by

ModelTest were then used in the ML analysis. The model selected for the ITS data set was the TrN + Γ model (Tamura & Nei 1993; Yang 1994); parameter values were freqA

= 0.2156, freqC = 0.2753, freqG = 0.3065, freqT = 0.2026, and gamma shape = 0.5294.

A heuristic search was conducted using 100 random addition replicates and TBR branch swapping. Support for branches was assessed using the same likelihood model with 500 bootstrap replicates, 10 random additions per replicate, and TBR branch swapping, MULTREES option in effect.

Results and discussion

For the entire ITS region, 966 nucleotide sites were included in the analysis. Of these sites, 624 were constant, 342 were variable, and 162 were phylogenetically informative. Parsimony analysis of the ITS dataset resulted in 12 most parsimonious trees with a length of 603 steps (CI = 0.73; RI = 0.79). The strict consensus tree (with branch support assessed by the bootstrap analysis, Fig. 2-1), and a representative cladogram (Fig. 2-2) are presented. Maximum likelihood analysis recovered a single best tree (Fig. 2-3) with –ln likelihood score of 4278.44028.

The topologies derived from the strict consensus of the parsimony trees (Fig. 2-

1) and the ML tree (Fig. 2-3) are nearly identical. They show that the eight species putatively belonging in the North American clade do in fact appear together in a clade

with 100% bootstrap support. Thus, ITS sequence data, in agreement with the putative morphological synapomorphies listed above, support the monophyly of the North

American clade, and these analyses confirm that all eight endemic North American species are included within it. This clade will henceforth be referred to as Sideroxylon section Frigoricola (see Chapter 5). A subgrouping of five species (i.e., S. lanuginosum,

S. rufohirtum, S. lycioides, S. alachuense, and S. tenax–inland Florida ridge) appears within sect. Frigoricola in the ML tree, but this grouping has negligible bootstrap support

(52%). Thus, ITS sequence data fails to resolve relationships among the species within the section. The tree topologies presented here (Figs. 2-1, 2-3) closely reflect that of

Smedmark and Anderberg (2007, Fig. 2), with Sideroxylon section Frigoricola sister to a clade containing selected tropical members of the Bumelia clade, the two sister clades forming the Bumelia clade with strong bootstrap support. A second Neotropical clade including members of the former segregate genera Dipholis and Mastichodendron (i.e., the well-supported clade G, Fig. 2, Smedmark & Anderberg 2007), appears in these analyses represented by S. capiri, S. foetidissimum, S. stevensonii, and S. cubense, with moderate to strong bootstrap support. The present analyses, as well as those of

Smedmark and Anderberg (2007) and Stride et al. (2014), suggest that formerly recognized segregate genera may represent subclades within Sideroxylon. Future analyses employing more thorough taxon sampling will indicate whether or not these subclades are worthy of taxonomic recognition as subgenera of Sideroxylon.

Table 2–1. List of taxa, vouchers, and GenBank accession numbers for DNA sequences included in cladistic analyses of Sideroxylon species. Accession no.(ITS, rpL32-trnL, trnL-trnF, atpB-rbcL, accD-psaI, Taxon Voucher trnV-ndhC) Argania spinosa Nordenstam 9325, Morocco (S) AM408056 Sarcosperma laurinum Saunders 2000, Hong Kong (S) AM408055 Sideroxylon alachuense Corogin 1037, Florida, USA (FLAS) Sideroxylon americanum Gillis 11576, Bahamas (B) AM408060 Sideroxylon capiri Garcıa 1848, Mexico (BM, S) AM408065 Sideroxylon celastrinum Corogin 1058, Florida, USA (FLAS) Sideroxylon cubense Beurton & Mory 927, Dominican Rep. (B) AM408070 Sideroxylon foetidissimum Lundin 638, Cuba (S) AM408072 Sideroxylon horridum Gutierrez & Nilsson 5, Cuba (S) AM408076 Sideroxylon inerme Nielsen s.n., Cult. Denmark (S) AM408078 Sideroxylon lanuginosum Corogin 1001, Florida, USA (FLAS) Sideroxylon leucophyllum Carter 5706, Mexico (BM) AM408080 Sideroxylon lycioides Estes 09191, Tennessee, USA (TENN) Sideroxylon macrocarpum Allison 9766, Georgia, USA (USCH) Sideroxylon majus Capuron 28185_SF, Reunion (B) AM408082 Sideroxylon obtusifolium Alvarez et al. 28772, Mexico (B) AM408087 Sideroxylon palmeri Palmer 1513, Mexico (S) AM408090 Sideroxylon persimile Veliz 99.7038, Guatemala (BM) AM408091 Sideroxylon reclinatum subsp. reclinatum Corogin 1025, Florida, USA (FLAS) Sideroxylon reclinatum subsp. austrofloridense Corogin 1052, Florida, USA (FLAS) Sideroxylon rufohirtum Corogin 999, Florida, USA (FLAS) Sideroxylon salicifolium Gutierrez & Nilsson 14, Cuba (S) AM408098 Sideroxylon saxorum Jongkind 3500, Madagascar (WAG) AM408099 Sideroxylon stevensonii Lundell & Contreras 19057, Guatemala (S) AM408102 Sideroxylon tenax (Atlantic coast) Profant 35, Florida, USA, (FLAS) Sideroxylon tenax (inland Florida ridge) Corogin 1005, Florida, USA (FLAS) Sideroxylon thornei Allison 12257, Georgia, USA (USCH)

Figure 2-1. Strict consensus of 12 most parsimonious trees from analysis of ITS sequences for species of Sideroxylon sect. Frigoricola and selected tropical relatives (603 steps, CI = 0.73; RI = 0.79). Parsimony bootstrap values are given above lines.

Figure 2-2. Representative cladogram: one of 12 most parsimonious trees generated in analysis of ITS sequences.

Figure 2-3. Best tree generated by maximum likelihood analysis of ITS sequences for species of Sideroxylon sect. Frigoricola and selected tropical relatives. ML bootstrap values are given above lines.

CHAPTER 3 PHYLOGENETIC RELATIONSHIPS WITHIN SIDEROXYLON SECTION FRIGORICOLA BASED UPON MORPHOLOGY AND cpDNA SEQUENCES

Phylogenetic relationships and species circumscription among North American taxa of Sideroxylon have long been problematic. Characters chosen to diagnose one generic or specific group tend to overlap with those diagnosing another, and this led to subjectivity in choosing appropriate diagnostic characters for taxa during an era when phylogenetic and molecular methods were not yet available. Monographers (Gray 1886, Small 1900, Clark

1942, Cronquist 1945) have differed as to the number of species occurring in North

America; e.g., Clark (1942) recognized 14, while Cronquist (1945) recognized only five, and neither clearly explained their criteria for specific recognition. Since 1945, the subsequent recognition of S. thornei (Cronquist 1949), S. rufohirtum (Herring & Judd 1995), S. alachuense (Anderson 1997), and S. macrocarpum (Allison 2006) has brought that number to eleven species. Eight of these species (i.e., S. lycioides, S. thornei, S. tenax, S. alachuense, S. lanuginosum, S. reclinatum, S. rufohirtum, and S. macrocarpum) form the group endemic to North America, i.e., Sideroxylon sect. Frigoricola, and species boundaries within this section are here reassessed from a phylogenetic perspective (but see also

Taxonomy). The monophyly of the section is strongly supported by ITS sequence data (see previous chapter), but relationships among its eight species are poorly resolved. The molecular phylogenetic analyses of Smedmark and Anderberg (2007) and Stride et al.

(2014), which included four of these species (i.e., S. lycioides, S. tenax, S. lanuginosum, and S. reclinatum), did not resolve their relationships, although these analyses did group S. tenax with S. lycioides with weak to moderate support. To improve our understanding of the relationships among the species of Sideroxylon sect. Frigoricola, a morphology-based cladistic analysis was performed. Additionally, it was noted that, rivaled only by ITS

sequences, chloroplast DNA (cpDNA) sequences have been perhaps the most common data source used in plant molecular systematic studies (Shaw et al. 2005). Data from such sequences have been used successfully in recent studies of Sapotaceae and Sideroxylon

(Anderberg & Swenson 2003; Bartish et al. 2005; Swenson & Anderberg 2005; Swenson et al. 2007, 2008). Among cpDNA regions, the non-coding sequences, i.e., introns and intergenic spacers, often provide more variability than coding regions at the species level. In order to assess molecular variability among these eight species, several non-coding cpDNA markers were sequenced and analyzed.

Species and Subspecies Concepts

Species delimitation within Sideroxylon sect. Frigoricola are based on the morphological-phenetic species concept (Judd 1981; Judd & Beaman 1988; Judd et al.

2007), i.e., they are morphologically cohesive entities that are separated from others by consistent morphological gaps. This concept was applied in conjunction with a phylogenetic species concept as applied by Donoghue (1985), Mishler (1985), or Mishler and Theriot

(2000), i.e., the apomorphic species concept (Judd et al. 2007). In this approach,

“organisms are grouped into species because of evidence of monophyly” and “taxa are ranked as species rather than at some higher level because they are the smallest monophyletic groups deemed worthy of formal recognition” (Mishler & Theriot 2000, p. 46,

47). Thus, I have attempted to assess whether or not each phenetically circumscribed species could be hypothesized as monophyletic, i.e., recognized as a cladospecies. Entities that are phenetically cohesive but composed of unresolved lineages lacking clear evidence of monophyly are treated as metaspecies (Donoghue 1985). I have also applied the phylogenetic species concept of Cracraft (1989), Nixon and Wheeler (1990), Davis and

Nixon (1992, p. 427), and Wheeler and Platnick (2000, p. 58), i.e., “the smallest aggregation

of populations … diagnosable by a unique combination of character states in comparable individuals,” an approach often called the diagnosable species concept (Judd et al. 2007).

Delimitation of subspecies follows the proposal by Ellison et al. (2014, p. 946):

“Subspecies comprise evolving populations that represent partially isolated lineages of a well-defined species that are either allopatric or sympatric, phenotypically distinct, have at least one fixed diagnosable character state, and that these character differences are, or are assumed to be, correlated with at least partial evolutionary independence according to population genetic structure.” In Sideroxylon sect. Frigoricola, subspecies as delimited here are entities occupying a distinct geographic range within the species range, and intergrading with other subspecies where their ranges meet, i.e., subspecies sensu Cronquist (1943).

(See Taxonomy for further discussion of subspecies concepts).

Materials and Methods

General Morphology

During this study ca. 3190 specimens were examined. Of these, 219 specimens were collected by me, on numerous field trips in Florida and Georgia, representing all the species of Sideroxylon section Frigoricola except S. lycioides and the western subspecies of S. lanuginosum. The remaining specimens were from the herbaria listed in the

Acknowledgments. Abbreviations follow Thiers (2015). Measurements of floral parts were taken from fresh material when possible, or from material preserved in FAA (37% formaldehyde solution [5%], glacial acetic acid [5%], 70% ethanol [90%]), or from dried material rehydrated by boiling several minutes in water with a small amount of detergent added. Flowers were dissected with the aid of a Wild M5A dissecting microscope (Aarau,

Switzerland). Other measurements were taken directly from dried material. Dimensions of trichomes were measured with the aid of a Carl Zeiss 4311036 compound microscope.

Plant height, trunk diameter, and flower color were recorded in the field when possible, but photographs and data from herbarium specimen labels were also used. Scanning electron microscopy (SEM) was employed for examination of leaf surface micromorphology. Leaf material from dried herbarium specimens of taxa being compared was mounted on carbon adhesive tabs on aluminum specimen mounts. Samples were rendered conductive by coating with a gold-palladium alloy in argon vacuum for 90 seconds using a Denton Desk V sputter coater (Denton Vacuum, Moorestown, NJ, USA). Samples were examined with a

Hitachi S-4000 field-emission scanning electron microscope (Hitachi High Technologies

America, Inc. Schaumburg, IL), and digital micrographs were acquired with PCI Quartz software. SEM work was conducted at the Electron Microscopy Core of the Interdisciplinary

Center for Biotechnology Research (ICBR) at the University of Florida.

Morphological Cladistic Analysis

A morphology-based cladistic analysis of the species of Sideroxylon section

Frigoricola was conducted using the parsimony-based algorithms employed in the PAUP*

4.0b10 software developed by Swofford (2002). Twenty-five morphological characters were delimited and assigned states (Tables 3-1 and 3-2) based on my observations of herbarium specimens, and, where possible, observations of living plants. These characters were readily divisible into discrete states; arbitrary decisions with regard to state delimitation were thus avoided (see Stevens 1991). Most of the characters are qualitative, but a few are quantitative (see Table 3-1). Many measured characters could not be included in the analysis because they exhibited too much infrataxon variation or could not be easily delimited into discrete states, e.g., internode length, leaf length and width, pedicel length, sepal dimensions, corolla tube and corolla lobe dimensions, filament and anther length, ovary size, ovary pubescence, and fruit and seed dimensions. Taxa polymorphic for

particular binary characters were scored as “?” (Table 3-2). Three outgroups, Sideroxylon celastrinum, S. americanum, and S. salicifolium, were selected based on the molecular phylogenetic analyses of Smedmark and Anderberg (2007) and Stride et al. (2014).

Sideroxylon celastrinum and S. americanum are members of the tropical portion of the

Bumelia clade, a group that is monophyletic and sister to the North American portion of the

Bumelia clade, i.e., Sideroxylon sect. Frigoricola. Sideroxylon salicifolium belongs to the

Dipholis/Mastichodendron clade, a group outside of the Bumelia clade (Smedmark and

Anderberg 2007, Stride et al. 2014). Therefore, the tree resulting from the analysis was rooted using S. salicifolium. The character state polarizations given in Table 3-1 are based on the results of the PAUP* analysis, based on these three outgroup species. The analysis was run using the branch-and-bound algorithm, with the MulTrees option in effect. Strength of support for clades revealed in the analyses was assessed using bootstrap support

(Felsenstein 1985). Bootstrap analyses (1000 replicates) were conducted using a heuristic search, with TBR branch swapping, 10 random additions per replicate. Twenty-four of the 25 characters were parsimony-informative, and all characters were considered of equal weight.

Chloroplast DNA Analysis

For the eight species of Sideroxylon section Frigoricola, i.e., Sideroxylon lycioides, S. tenax (including both Atlantic coast and inland Florida ridge populations), S. lanuginosum, S. reclinatum (both subspecies), S. thornei, S. alachuense, S. rufohirtum, and S. macrocarpum, and one outgroup, S. celastrinum, I attempted to amplify and sequence the following 11 non-coding cpDNA regions: psbD-trnT, trnH-trnK, trnS-trnfm, trnQ-rps16, trnC- trnD, trnL-trnF, atpB-rbcL, accD-psaI, rpoB-trnC, rpL32-trnL, and trnV-ndhC, using primers based on Shaw et al. (2005; 2007). Procedures for DNA extraction, PCR amplification and sequencing were the same as those outlined in Materials and Methods of the previous

chapter, except for the PCR reaction components and the thermocycler program, which are as follows. The reaction components for cpDNA: 1 µL of template DNA (approximately 10–

100 ng), 18 µL of water, 2.5 µL of 10 × buffer, 2 µL of MgCl2 (25 mM), 0.5 µL of 10 mM dNTPs, 0.5 µL each of 10 µM primers and 0.5 units (0.2 µL) of Taq DNA polymerase. Each cpDNA region was amplified with a touchdown thermal cycling protocol using the parameters 94 °C for 3 min; 33 × (94 °C for 30 s; 55 °C for 30 s; 72 °C for 2 min); 72 °C for

4 min, using primers based on Shaw et al. (2005; 2007). Successfully-obtained sequences were deposited in GenBank (see Table 2-1). For those cpDNA regions for which amplification and sequencing were successful, i.e., rpL32-trnL, trnL-trnF, atpB-rbcL, accD- psaI, and trnV-ndhC, sequences were edited in Sequencher version 4.10.1 (Gene Codes

Corporation 2010), and manually aligned using SeaView version 4 (Galtier et al. 1996, Gouy et al. 2010). These five cpDNA sequences were combined into a single dataset and subjected to phylogenetic analyses employing both maximum parsimony (MP) and maximum likelihood (ML) optimality criteria. Analyses were also performed on a combined dataset of ITS plus the five cpDNA sequences.

Parsimony analyses were done using PAUP* 4.0b10 (Swofford 2002), using the branch-and-bound search option with equally-weighted characters, gaps treated as missing,

MaxTrees setting 200, MulTrees option in effect. Strength of support for clades revealed in the analysis was assessed using bootstrap analysis (Felsenstein 1985) with 1000 replicates, using a heuristic search, with TBR branch swapping, 10 random additions per replicate.

Maximum likelihood analyses were carried out using RAxML version 8 (Stamatakis

2014) on the CIPRES online portal (http://www.phylo.org/portal2; Miller et al. 2010), under the GTR + Γ model. Model parameter values for the analysis of the cpDNA dataset were freqA = 0.375019, freqC = 0.143546, freqG = 0.134537, freqT = 0.346898, and gamma

shape (alpha) = 1.014019; for the combined ITS + cpDNA dataset the values were freqA=0.340404, freqC=0.172243, freqG=0.169467, freqT=0.317886, and alpha=0.111638.

Bootstrap support for branches was assessed using the GTR + Γ model, with 1000 replicates.

Because the tree topologies of the morphological and molecular phylogenies resulting from my MP and ML analyses were only weakly supported, I used Mesquite v. 3.02

(Maddison & Maddison 2015) to construct five different constraint trees, to compare the hypothesis suggested by the morphological phylogeny to hypotheses suggested by groupings appearing in the molecular phylogenies. The five constraint trees were as follows:

1) S. lycioides sister to S. alachuense; 2) S. tenax sister to S. reclinatum subsp. austrofloridense; 3) a tree with both S. lycioides sister to S. alachuense, and S. tenax sister to S. reclinatum subsp. austrofloridense; 4) a tree with topology identical to that of the cpDNA tree; 5) a tree with topology identical to that of the ITS + cpDNA tree. I then used MP in PAUP* and the Templeton test (Templeton 1983) to compare the lengths and statistical differences between the morphological tree and the trees recovered based on the five constraints. Tree searches were branch-and bound, with MULTREES option in effect.

Results and Discussion

Morphological Cladistic Analysis

The morphological analysis generated a single most-parsimonious tree of 40 steps

(Fig. 3-1), with a consistency index (CI) of 0.625, and a retention index (RI) of 0.7. The monophyly of the ingroup, Sideroxylon section Frigoricola (clade H, Fig. 1), was supported by a bootstrap value of 94%. This group has a suite of putative morphological synapomorphies, including adaxially channeled petioles (character 4, Table 3-1), leaves with tertiary vein reticulum conspicuous adaxially (character 6) and marginal vein lacking

(character 7), T-shaped trichomes of the abaxial leaf surface with upper portions greater than 0.6 mm long (character 13), tops of stomatal chambers elevated above the surrounding cuticular surface (character 19), and seeds with a bipartite hilum scar (character 25). Within

Sideroxylon section Frigoricola, five terminal clades are evident, and relationships among them are well-resolved: 1) the S. lycioides + S. thornei clade, sister to the remaining taxa in the section; 2) the Sideroxylon tenax clade (i.e., S. tenax + S. alachuense, bootstrap 71%), sister to the remaining taxa in the section; 3) the Sideroxylon lanuginosum clade (i.e., S. lanuginosum subspp. lanuginosum, rigidum, and albicans); 4) the Sideroxylon reclinatum clade (i.e., S. reclinatum subspp. reclinatum and austrofloridense) and 5) the S. rufohirtum +

S. macrocarpum clade. Additional clades worth noting are the Sideroxylon reclinatum complex (i.e., S. reclinatum subsp. reclinatum + S. reclinatum subsp. austrofloridense + S. rufohirtum + S. macrocarpum), and a clade containing all the species in the section excluding S. lycioides and S. thornei.

The morphological diagnoses of these clades are given below. For additional details concerning characters useful in distinguishing these groups, see the key and discussions under each species treatment (see Taxonomy chapter). Character numbers refer to Tables

3-1 and 3-2.

Clade A: The Sideroxylon lycioides + S. thornei clade is supported by neatly dome- shaped stomatal chambers with openings a narrow slit, hiding the guard cells (character 20), and glabrous pedicels (character 21). The narrow-slit stomatal chamber opening is unique to this clade; all the other species in the analysis have wide, elliptical stomatal chamber openings, with the guard cells visible through the opening.

Clade B: The Sideroxylon tenax clade includes S. tenax, including its Atlantic coastal and interior Florida sand ridge variants (see Taxonomy), along with the narrowly endemic S.

alachuense. The group shares the following apomorphies: abaxial leaf epidermis of older leaves always obscured by pubescence (character 8), and stomatal chamber dome complexes in which concentric cuticular ridges around the dome form a raised, donut- shaped structure fused with the border of the chamber opening, the opening centered in the structure and flush with its top or slightly depressed below it (character 17). This clade received 71% bootstrap support in the analysis.

Clade C: The Sideroxylon lanuginosum clade (i.e., S. lanuginosum subspp. lanuginosum, rigidum, and albicans) has the synapomorphy of T-shaped trichomes of the abaxial leaf surface with a stalk consistently greater than 0.1 mm in length (character 12).

This longer stalk lifts the top portions of the trichomes well clear of the leaf surface, giving the pubescence a loose and open appearance, even when it is dense.

Clade D: The Sideroxylon reclinatum clade (i.e., S. reclinatum subsp. reclinatum and subsp. austrofloridense) is supported by the apomorphy of young twigs with pubescence absent or quickly deciduous (character 3).

Clade E: The Sideroxylon rufohirtum + S. macrocarpum clade is supported by the apomorphy of strong clonality, with mature aerial shoots typically less than 1 m tall

(character 1).

Clade F: The Sideroxylon reclinatum complex (i.e., S. reclinatum subsp. reclinatum +

S. reclinatum subsp. austrofloridense + S. rufohirtum + S. macrocarpum) forms a clade supported by glabrous pedicels (character 21), although this character becomes polymorphic in S. reclinatum subsp. austrofloridense and S. rufohirtum.

Clade G: Sister to the S. lycioides + S. thornei clade is a clade containing all the remaining species in the section. This clade can be diagnosed by the structure of the stomatal chamber dome complexes, in which the concentric cuticular ridges surrounding the

dome are one to many and irregularly formed, creating a broad, oval to circular series of rings around the dome (character 18), in contrast to the S. lycioides + S. thornei clade and the outgroups, in which concentric ridges surrounding the dome are one to three and neatly formed, tightly bordering the base of the dome. Additional apomorphies are leaves usually with a rounded apex (character 5, DELTRAN optimization), and leaf trichomes that are terete in cross-section (character 10), although this latter character becomes polymorphic in

S. tenax and in the S. reclinatum complex.

Chloroplast DNA Analysis

Of the eleven cpDNA regions chosen for screening, amplification and sequencing were successful for five, i.e., rpL32-trnL, trnL-trnF, atpB-rbcL, accD-psaI, and trnV-ndhC.

The regions rpL32-trnL, trnL-trnF, and atpB-rbcL were successfully sequenced for all eight species, i.e., Sideroxylon lycioides, S. tenax (including both Atlantic coast and inland Florida ridge populations), S. lanuginosum, S. reclinatum (both subspecies), S. thornei, S. alachuense, S. rufohirtum, and S. macrocarpum, and the outgroup, S. celastrinum. The region accD-psaI was successfully sequenced only for S. lycioides, S. alachuense, S. thornei, S. reclinatum subsp. reclinatum, and S. macrocarpum. The region trnV-ndhC was successfully sequenced for all except S. lycioides and S. macrocarpum.

For the combined dataset of five cpDNA regions, MP analysis resulted in 20 most parsimonious trees with a length of 68 steps, CI = 0.83; RI = 0.83. The strict consensus tree

(Fig. 3-2) and a representative cladogram (Fig. 3-3) are presented. ML analysis recovered a single best tree (Fig. 3-4) with –ln likelihood score of 8005.674598. In the strict consensus for the MP analysis, the ingroup is unresolved, except for a clade containing S. lycioides +

S. alachuense, which received 67% bootstrap support (Fig. 3-2). The ML tree (Fig. 3-4) shows more resolution, but with a topology quite different from that of the morphology tree

(Fig. 3-1). Most notable in the cpDNA tree are two groupings not seen in the morphology tree, i.e., a S. lycioides + S. alachuense clade as in the MP tree (bootstrap 65%), and a clade containing S. tenax (coastal) + S. reclinatum subsp. austrofloridense, which received moderately strong bootstrap support (89%).

Combined ITS + cpDNA Datasets

The ML trees from ITS (Fig. 2-3) and combined cpDNA (Fig. 3-4) are not topologically congruent. However, the contradictions are only weakly supported (bootstrap <70%), with the exception of a clade that appears in the cpDNA phylogeny, containing S. tenax (coastal) and S. reclinatum subsp. austrofloridense, which received 89% bootstrap support. The ITS and cpDNA datasets analyzed in this study have relatively few potentially phylogenetically informative variable characters (see Table 3-3). This paucity of informative characters could account for some of the incongruence between ITS and cpDNA, and combining datasets would increase the number of characters (Kluge & Wolf 1993; Johnson & Soltis 1998).

Therefore, ITS was combined with cpDNA, and this combined dataset was analyzed as for the cpDNA dataset above. MP analysis yielded five most-parsimonious trees with a length of

142 steps, CI=0.67, RI=0.69. The strict consensus tree (Fig. 3-5), and a representative cladogram (Fig. 3-6) are presented. ML analysis recovered a single best tree (Fig. 3-7) with

–ln likelihood score of –8005.674598. In the strict consensus for the MP analysis, the ingroup is unresolved except for a clade containing S. lycioides + S. alachuense, which received 66% bootstrap support (Fig. 3-5), and is nested within a group with bootstrap support <50% containing S. lanuginosum, S. rufohirtum, and S. tenax (inland ridge). The ML tree (Fig. 3-7) shows more resolution, but with a topology again quite different from that of the morphology tree (Fig. 3-1). Most notable in the combined ITS + cpDNA tree are the same two moderately supported groupings seen in the cpDNA tree (Fig. 3-4), which are not

seen in the morphology tree, i.e., a S. lycioides + S. alachuense clade as in the MP tree

(bootstrap 72%), and a clade containing S. tenax (coastal) + S. reclinatum subsp. austrofloridense (bootstrap 73%).

Comparison of Phylogenies

The discordance between the morphological and molecular phylogenies, and also between the cpDNA and ITS + cpDNA trees, presents a confusing picture. The morphological phylogeny (Fig. 3-1) is well resolved and reflects groupings intuitively recognizable in the field, although its subclades are only weakly supported. The differing topologies of the two molecular trees (Figs. 3-4, 3-7) are also only weakly supported, except for two clades appearing in both trees and receiving bootstrap support greater than 60%, i.e., S. lycioides + S. alachuense, and S. tenax (coastal) + S. reclinatum subsp. austrofloridense. From the viewpoint of one who has observed these species in the field and examined numerous specimens, these two groupings are counterintuitive: the coastal and inland variants of S. tenax do not group together, one of them grouping instead with the morphologically and eco-geographically dissimilar S. reclinatum subsp. austrofloridense.

Moreover, S. alachuense, whose morphological similarity to S. tenax is strikingly obvious, groups not with S. tenax but instead with the morphologically dissimilar S. lycioides. Also notable in the molecular trees is that S. macrocarpum and S. rufohirtum appear in separate clades, and in the ITS + cpDNA tree, the two subspecies of S. reclinatum are not grouped together, but rather each is grouped with a morphologically dissimilar species.

Given the low to bootstrap support received by any of these alternative topologies, tree lengths were compared among the single most parsimonious tree from the morphological analysis (Fig. 3-1, 40 steps) and five constraint trees. Each tree search under the constraints recovered a single most-parsimonious tree. The tree recovered under the

constraint topology identical to the cpDNA tree had a length of 48 steps, and the Templeton test indicated the difference was statistically significant (p=0.04). The tree recovered under the constraint topology identical to the ITS + cpDNA tree had a length of 49 steps, and the difference was statistically significant (p=0.01). The tree recovered under the constraint of having both S. lycioides sister to S. alachuense, and S. tenax sister to S. reclinatum subsp. austrofloridense had a length of 47 steps, and the difference was statistically significant

(p=0.02). The tree recovered under the constraint of having S. tenax sister to S. reclinatum subsp. austrofloridense had a length of 45 steps, and the difference was statistically significant (p=0.03). Finally, the tree recovered under the constraint of having S. lycioides sister to S. alachuense had a length of 45 steps, but the difference between this tree and the morphological phylogeny (40 steps) was not statistically significant (p=0.09).

All but one of the constraint-based trees is significantly less parsimonious than the morphological phylogeny, which leads me to have more confidence in the morphological results. However one clade perhaps bears special consideration, because it was recovered, with bootstrap support >60%, in both the MP and ML analyses for both the cpDNA and ITS

+ cpDNA datasets, i.e., the clade containing S. lycioides + S. alachuense. The constraint- based tree for this clade, although longer by 5 steps than the morphological phylogeny, was not statistically significantly different. The published molecular phylogenies of Smedmark &

Anderberg (2007, Fig.2) and Stride et al. (2014, Fig. 1) show S. lycioides grouped with S. tenax, the latter presumably closely related to S. alachuense. All of this suggests a possible close relationship between S. lycioides, S. tenax, and S. alachuense. Such a relationship is not suggested by my morphological analysis, which instead groups S. lycioides with S. thornei (albeit without any bootstrap support) based on the remarkable similarity of stomatal chamber micromorphology between these two species. The stomatal complex of these two

species is strikingly different from that of all the other species of Sideroxylon sect.

Frigoricola. Because I find this stomatal chamber micromorphological character quite convincing, my preference is to recognize the S. lycioides + S. thornei grouping.

I believe it is worth noting the low proportion of potentially informative variable sites in the molecular datasets used in the analyses for this study (see Table 3-3). ITS and cpDNA sequences, while quite useful at higher classificatory levels, often fail to exhibit enough nucleotide variability to resolve phylogenies of closely related taxa (Despres et al. 2002;

Edwards et al. 2006, 2009), and even multilocus cpDNA analyses may have limits to their ability to discriminate among plant species regardless of the degree of variability at the chosen loci (Fazekas et al. 2009). For this reason I am inclined at this time to place more confidence in the morphological phylogeny (Fig. 3-1) as more accurately representing relationships among the species of Sideroxylon sect. Frigoricola. Future molecular studies at the population genetic level may prove useful for testing this morphology-based hypothesis.

Assessment of Phylogenetic Species

Putative autapomorphies were included in the morphological cladistic analysis presented above, allowing the assessment of species-level monophyly, i.e., whether or not each species is monophyletic, paraphyletic, or metaphyletic (unresolved). Even under a phylogenetic species concept, non-monophyletic species are commonly recognized (Crisp &

Chandler 1996). Putative autapomorphies for species of Sideroxylon section Frigoricola are listed in Table 3-4, along with an assessment of whether each species is a cladospecies or a metaspecies (following terminology of Donoghue 1985). All but one of these species exhibit one or more autapomorphies, therefore they are considered to be cladospecies according to the apomorphic species concept (see Donoghue 1985; Mishler 1985; Mishler &

Theriot 2000). One species, S. tenax, may be a metaspecies; it shows no autapomorphies

when compared with the related S. alachuense. The narrowly endemic S. alachuense has sometimes been considered conspecific with the more widespread S. tenax (e.g., Cronquist

1945); the former may have arisen from the latter. All of the species are morphologically distinctive, and fit the diagnosable species concept (Wheeler & Platnick 2000). The high frequency of cladospecies in this group suggests that although molecular divergence within the group is minimal (see previous chapter), sufficient time has passed since the events leading to speciation that one to several morphological novelties have become fixed within nearly all of the groups of populations here recognized at the species level.

Table 3-1. Characters used in the morphology-based phylogenetic analysis of species of Sideroxylon sect. Frigoricola. Presumed apomorphic character states are listed first (1), followed by the plesiomorphic state (0). Character number Character states 1. Plant strongly clonal, height usually less than 1 m (1); plant not strongly clonal, height usually greater than 1 m (0). 2. Surface of young twig cream-white to light grey (1); surface of young twig red-brown (0). 3. Pubescence of young twig absent or quickly deciduous (1); pubescence of young twig persistent through first season (0). 4. Petiole canaliculate (1); petiole not canaliculate (0). 5. Leaf apex usually rounded (1); leaf apex usually acute to acuminate (0). 6. Tertiary vein reticulum conspicuous (1); tertiary vein reticulum obscure (0). 7. Marginal vein absent (1); marginal vein present (0). 8. Abaxial epidermis of older leaves obscured by pubescence (1); abaxial epidermis of older leaves visible, not obscured by pubescence (0). 9. Leaf abaxial: upper portions of T-shaped trichomes nearly all bent or curled (1); upper portions of T- shaped trichomes nearly all straight (0). 10. Leaf abaxial: trichomes nearly all terete in cross-section (1); trichomes nearly all flattened in cross- section (0). 11. Leaf abaxial: upper portions of T-shaped trichomes not co-oriented (1); upper portions of T-shaped trichomes co-oriented (0). 12. Leaf abaxial: mean length of stalk of T-shaped trichomes greater than 0.1 mm (1); mean length of stalk of T-shaped trichomes less than 0.08 mm (0). 13. Leaf abaxial: mean length of upper portion of T-shaped trichomes greater than 0.6 mm (1); mean length of upper portion of T-shaped trichomes less than 0.5 mm (0). 14. Leaf abaxial: trichomes always transparent (1); trichomes transparent to semi-opaque (0). 15. Leaf abaxial: trichomes colorless (1); trichomes pigmented (0). 16. Abaxial leaf epidermis: bands of parallel cuticular ridges extending radially outward from stomatal chamber openings, if present at all, occurring on few to many (but never all or nearly all) stomata, the surface between stomata variously ornamented but not extensively covered by such bands (1); broad bands of very fine grained, parallel cuticular ridges extending radially outward from all or nearly all stomatal openings and often meandering, the surface between stomata extensively ornamented with these bands (0).

Table 3-1. Continued. Character number Character states

17. Stomatal chamber dome complex: concentric cuticular ridges around dome forming a raised, donut- shaped structure fused with border of chamber opening, the opening centered in the structure and flush with its top or slightly depressed below it (1); concentric cuticular ridges around dome (if present) forming a series of rings around chamber opening but not fused with its border, the opening raised above the ridges or flush with them (0). 18. Stomatal chamber dome complex: concentric cuticular ridges around dome one to many, irregularly formed, creating a broad, oval to circular series of rings around dome (1); concentric ridges around dome one to three (or absent), neatly formed, tightly bordering base of dome (0). 19. Stomatal chamber dome complex elevated (at least slightly) above surrounding cuticular surface (1); stomatal chamber dome complex recessed in a depression in cuticular surface (0). 20. Stomatal chamber opening a narrow slit, guard cells hidden (1); stomatal chamber opening wide, elliptic, guard cells visible (0). 21. Pedicels always glabrous at anthesis (1); pedicels always pubescent at anthesis (0). 22. Sepals always glabrous at anthesis (1); sepals always pubescent at anthesis (0). 23. Ovary tapering abruptly to style (1); ovary tapering gradually to style (0). 24. Style length less than 2.5 mm (1); style length greater than 2.5 mm (0). 25. Hilum scar bipartite (1); hilum scar unipartite (0).

Table 3-2. Character values used in morphological cladistic analysis for species of Sideroxylon section Frigoricola (and three outgroups, S. salicifolium, S. americanum, and S. celastrinum). 1 = apomorphic, 0 = plesiomorphic, ? = 0/1. 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 Character number 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5

S. salicifolium (outgroup) 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 S. americanum (outgroup) 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 1 0 0 S. celastrinum (outgroup) 0 0 0 0 1 0 0 0 0 0 1 0 0 0 ? 1 0 0 0 0 1 0 1 0 0 S. lycioides 0 0 1 1 0 1 1 0 0 0 0 0 1 1 1 1 0 0 1 1 1 1 1 1 1 S. thornei 0 0 0 1 0 1 1 0 1 0 1 1 1 0 0 0 0 0 1 1 1 0 0 1 1 S. tenax 0 0 0 1 1 1 1 1 ? ? 0 0 1 0 0 1 1 1 1 0 0 0 1 1 1 S. alachuense 0 1 1 1 1 1 1 1 0 1 0 0 1 1 ? 1 1 1 1 0 0 0 1 1 1 S. lanuginosum subsp. lanuginosum 0 0 0 1 1 1 1 0 1 1 1 1 1 0 ? 1 0 1 1 0 ? 0 1 1 1 S. lanuginosum subsp. rigidum 0 0 0 1 1 1 1 0 1 1 1 1 1 0 ? 1 0 1 1 0 ? ? 1 1 1 S. lanuginosum subsp. albicans 0 0 0 1 1 1 1 0 ? 1 1 1 1 0 1 1 0 1 1 0 0 0 1 1 1 S. reclinatum subsp. reclinatum 0 0 1 1 1 1 1 0 ? ? 1 0 1 0 ? 1 0 1 1 0 1 1 1 1 1 S. reclinatum subsp. austrofloridense 0 0 1 1 1 1 1 0 1 ? 1 0 1 0 ? 1 0 1 1 0 ? ? 1 1 1 S. rufohirtum 1 0 0 1 1 1 1 0 1 ? 1 0 1 0 0 1 1 1 1 0 ? 0 1 1 1 S. macrocarpum 1 0 0 1 1 1 1 0 1 ? 1 0 1 0 0 1 0 1 1 0 1 ? 1 1 1

Table 3-3. Character totals for DNA regions and combined datasets analyzed for species of Sideroxylon sect. Frigoricola. Numbers are from the log files of parsimony analyses conducted in PAUP*. Parsimony- Total Constant Variable informative characters characters characters characters trnV-ndhC 482 473 9 1 rpL32-trnL 1014 988 26 3 trnL-trnF 935 924 11 0 atpB-rbcL 516 509 7 0 accD-psaI 1080 1075 5 0 ITS 882 813 69 3 Combined cpDNA 4483 4416 67 5 Combined ITS + cpDNA 5365 5229 136 8

Table 3-4. Putative autapomorphies for species of Sideroxylon section Frigoricola. Character numbers follow Table 3-1. Species Putative autapomorphies S. lycioides Cladospecies. Pubescence of young twig absent or quickly deciduous (character 3), abaxial leaf trichomes always transparent (character 14), abaxial leaf trichomes unpigmented (character 15), sepals always glabrous at anthesis (character 22). S. thornei Cladospecies. Upper portions of abaxial leaf trichomes nearly all bent and curled (character 9), upper portions of abaxial leaf trichomes not co-oriented (character 11), stalk of T-shaped abaxial leaf trichomes greater than 0.1 mm in length (character 12), broad bands of very fine grained, parallel cuticular ridges extending radially outward from all or nearly all stomatal openings and often meandering, the surface between stomata extensively ornamented with these bands [character 16 (0)], ovary tapering gradually to style [character 23 (0)]. S. tenax Possibly a metaspecies (when compared with S. alachuense). S. alachuense Cladospecies. Young twigs cream-white to light grey (character 2), pubescence of young twig absent or quickly deciduous (character 3), abaxial leaf trichomes always transparent (character 14). S. lanuginosum Cladospecies. Stalk of T-shaped abaxial leaf trichomes greater than 0.1 mm in length (character 12). S. reclinatum Cladospecies. Pubescence of young twig absent or quickly deciduous (character 3). S. rufohirtum Cladospecies. Stomatal chamber dome complexes in which concentric cuticular ridges around the dome form a raised, donut-shaped structure fused with the border of the chamber opening, the opening centered in the structure and flush with its top or slightly depressed below it (character 17). S. macrocarpum Cladospecies. Staminodes reaching only 2/3 the length of median corolla lobe (not used in cladistic analysis).

Figure 3-1. Single most parsimonious tree from morphological analysis (40 steps, CI = 0.625, RI = 0.7). Parsimony bootstrap values above 50% are given below lines. Putative morphological synapomorphies for clades are as follows (character numbers refer to Table 3-1): A) 20, 21. B) 8, 17. C) 12. D) 3. E) 1. F) 21. G) 5 (DELTRAN), 10, 18. H) 4, 6, 7, 13, 19, 25.

Figure 3-2. Strict consensus of 20 most parsimonious trees from MP analysis of sequences from five cpDNA regions for species of Sideroxylon sect. Frigoricola and one outgroup (S. celastrinum). (68 steps, CI = 0.83; RI = 0.83). Parsimony bootstrap values above 50% are given above lines.

Figure 3-3. Representative cladogram: one of 20 most parsimonious trees generated in MP analysis of sequences from five cpDNA regions for species of Sideroxylon sect. Frigoricola and one outgroup (S. celastrinum).

Figure 3-4. Best tree generated by maximum likelihood analysis of sequences from five cpDNA regions for species of Sideroxylon sect. Frigoricola and one outgroup (S. celastrinum). ML bootstrap values above 50% are given above lines.

Figure 3-5. Strict consensus of five most parsimonious trees from MP analysis of combined dataset of ITS plus five cpDNA regions for species of Sideroxylon sect. Frigoricola and one outgroup (S. celastrinum). (142 steps, CI = 0.67; RI = 0.69). Parsimony bootstrap values above 50% are given above lines.

Figure 3-6. Representative cladogram: one of five most parsimonious trees generated in MP analysis of combined dataset of ITS plus five cpDNA regions for species of Sideroxylon sect. Frigoricola and one outgroup (S. celastrinum).

Figure 3-7. Best tree generated by maximum likelihood analysis of combined dataset of ITS plus five cpDNA regions for species of Sideroxylon sect. Frigoricola and one outgroup (S. celastrinum). ML bootstrap values above 50% are given above lines.

CHAPTER 4 ECOLOGY AND BIOGEOGRAPHY

Historical Biogeography of the Genus Sideroxylon

2010). During this span of time, the breakup of supercontinents Pangaea and

(ca. 55 Ma), by which time this fossil Sapotaceous pollen is found on all continents and exhibits similarities to all major modern groups within Sapotaceae (Harley 1991).

Boreotropical flora across much of the Northern Hemisphere (Wolfe 1975; Tiffney 1985;

Morley 2000). Smedmark and Anderberg (2007) hypothesized that Sideroxylon originated in Africa and arrived at its current pantropical distribution via the North

American Land Bridge ca. 55 Ma during the Late Paleocene-Early Eocene climatic maximum, which allowed the Boreotropical flora to spread beyond 50°N latitude, with

ranges of tropical species contracting to their current limits as global climate subsequently cooled in the Oligocene (Tiffney 1985; Morley 2000). But Stride et al.

The North American Coastal Plain: A Hotspot of Endemic Biodiversity

The flora of southeastern North America is biogeographically interesting. Over more than 50 million years of fluctuating global climate and sea levels, this area, stretching from the mid-Atlantic states westward across the southern Appalachians to coastal east Texas and northern Mexico, has had conditions ranging from subtropical to cool temperate, wet to dry, but never glaciated. During the glacial maxima of the ice ages, this area provided refugia for northern taxa and experienced compressed zones of vegetation types that created unique associations of species reflected in areas of high endemism seen today (Soltis et al. 2006). Several such centers of endemism have been identified in southeastern North America, most of which fall within the North

American Coastal Plain (NACP), a large natural physiographic region extending from southern New England southward through eastern Virginia and the Carolinas, southern

Georgia, all of Florida, west to eastern Texas, and south into Tamaulipas, Mexico (Estill

& Cruzan 2001; Sorrie & Weakley 2001, 2006; Noss et al. 2015). As defined by Sorrie and Weakley (2001), the coastal plain represents the exposed portion of the continental shelf, and includes also the Mississippi Embayment, where the plain extends up the

Mississippi valley to southern Illinois and southeastern Missouri. The physiographic

outlines of the NACP define the Coastal Plain Floristic Province, whose flora, in some places, is geologically relatively young due to repeated Pleistocene inundations, but has received inputs from older floras in the Appalachians, the Caribbean, western North

America, and parts of the coastal plain that escaped inundation (Webb 1990; Thorne

1993; Sorrie and Weakley 2001, 2006). Some parts of the NACP were never inundated, and have been climatically stable and continuously vegetated since the Late

Platt 1999; Drewa et al. 2002; Peet 2006; Noss et al. 2015). The portion of the NACP centered on Florida is surpassed only by the California floristic region in overall plant biodiversity and number of imperiled endemic taxa (Ward 1979; Gentry 1986; Sorrie and Weakley 2001; Stein et al. 2000). Florida’s centers of endemism are the subtropical southern tip of the peninsula, the Lake Wales Ridge in central Florida, and parts of the panhandle, especially the Apalachicola Bluffs (Ward 1979). Due to its unique scrub habitat, the degree of endemism on Florida’s Lake Wales Ridge is high by continental standards, exceeded only by islands such as Hawaii (Christman and Judd 1990; Stein et al. 2000; Zona & Judd 1986). Although the NACP has long been understood as an

area of high biodiversity and endemism, it has gone unrecognized in recent designations of global biodiversity hotspots (e.g., Myers et al. 2000; Mittermeier et al.

Sideroxylon section Frigoricola: A Group of NACP Endemics

The many narrow endemic taxa of the NACP have been of interest to taxonomists, not only for the intrinsic appeal of their rarity, but also because understanding the taxonomic relationships among such plants can help us understand patterns of speciation and biogeographic affinities. Some of these endemics have been well studied; for example, mints in the genera Dicerandra (Huck et al. 1989; Oliveira et al. 2007) and Conradina (Edwards et al. 2006, 2009), grasses in the Andropogon virginicus complex (Campbell 1983), pawpaws in the genus Asimina (Neubig & Abbott

2010; Chatrou et al. 2012), pitcher plants in the genus Sarracenia (Ellison et al. 2014), golden asters of the genus Chrysopsis (Semple 1981), and species in the genera

Hypericum (Adams 1962), Trillium (Freeman 1975), Polygonella (Nesom & Bates 1984);

Rhododendron (Kron 1993), Iris (Meerow et al. 2005), and Rhexia (Ionta et al. 2007).

But other groups of endemic taxa are in need of study. One such group is Sideroxylon section Frigoricola, the subject of the present monograph. This clade includes a number of narrow endemics; i.e., taxa with very restricted distributions (Fig. 4-1). The distributions of some of these taxa correspond with Florida’s three hotspots of endemism as discussed above. One taxon, S. reclinatum subsp. austrofloridense, is found only in the pine rocklands of the Everglades (Whetstone 1985). Another, S.

thornei, is restricted to a few counties in southern Georgia and the Florida panhandle

(Cronquist 1949, GDNR 2009). Still another, a morphologically distinct variant of S. tenax, once recognized as Bumelia lacuum (Small 1933, Lakela 1963), occurs only on the Lake Wales Ridge and adjacent sand ridges in the central Florida peninsula. Other narrow endemics have distributions not corresponding to these three hotspots, but nevertheless they are located within areas of coastal plain endemism identified by researchers (e.g., Estill & Cruzan 2001; Sorrie and Weakley 2001). For example,

Sideroxylon alachuense occurs in only a few scattered populations in Alachua, Marion,

Lake and Orange counties in north central Florida (Sargent 1921, Anderson 1997,

Wunderlin & Hansen 2008). Sideroxylon macrocarpum is restricted to a few populations in southeastern Georgia (Allison 2006, GDNR 2009), and S. rufohirtum is found only in a few counties in the northern and western Florida peninsula (Herring & Judd 1995).

Three of these taxa (S. alachuense, S. lycioides, and S. thornei) are listed as endangered by the State of Florida, and two taxa (S. macrocarpum and S. thornei) are listed as rare by the State of Georgia (Wunderlin and Hansen 2008; GDNR 2009).

These taxa occur in an array of soil types, habitats, and hydrological conditions, some taxa being separated from others by strict habitat preference, suggesting that these taxa have diversified ecologically.

Habitats and Distribution

Within Sideroxylon section Frigoricola, two species are widespread in their distribution. Sideroxylon lanuginosum has the broadest range, from northern Mexico,

Arizona, Texas, Oklahoma, and southern Kansas, Missouri, and Arkansas in the west, across the lower Mississippi valley and into the southern portions of Mississippi,

Alabama, and Georgia, south to central Florida. The species occurs mainly in mesic to

dry, sandy to rocky uplands, but also along streams and sometimes in river bottomland woods. It is usually associated with mixed hardwood species.

Sideroxylon lycioides is widely distributed in the southeast United States, from

Louisiana and extreme southeast Texas in the west, through the lower Mississippi valley as far north as southern Illinois and western Kentucky, southward through

Tennessee, Mississippi, Alabama, Georgia, South Carolina, along the coastal portions of North Carolina and Virginia, and sparingly into northern Florida. This species prefers moist to wet habitats, found along river and stream banks and bottomlands, and on adjacent slopes and bluffs, and on rocky outcrops.

The remaining species in the section are much more narrowly distributed.

Sideroxylon thornei has an interesting range, found in a narrow band of counties from

Gulf coastal Alabama and the western Florida panhandle northeastward into southwestern and south central Georgia, extending into two counties southeastern

Georgia. The range is centered on, and corresponds rather closely to, the Dougherty

Plain, an undulating flat area of sandy acidic soils overlying weathered limestone, which extends from southeastern Alabama and the northwestern Florida panhandle northeastward into southwestern Georgia (Thorne 1954; Gaillard 2009). Originally thought to be restricted to a few counties in southwestern Georgia, the range of S. thornei actually extends eastward into the Vidalia Upland in Georgia, and westward into the pine hills district of lower Alabama and the Florida panhandle. The species evidently originated in the Dougherty Plain, expanding to the east and west along a narrow zone of physiographic transition from the lower coastal plain to the south and east to higher elevations to the north and west. S. thornei is a shrub or small tree, associated with

other hardwood species in the understory of forested wet sandy bottomlands over limestone, and in woods bordering cypress ponds, in places where the soil is seasonally saturated but not completely inundated for long periods. The range of S. thornei overlaps with that of S. lycioides and S. reclinatum subsp. reclinatum, and their habitat preferences are similar in that they all prefer moist to mesic conditions and are usually associated with hardwood species. The morphological phylogeny of the present study

(Chapter 3) groups S. thornei in a clade as sister to the more widely distributed S. lycioides, both species sharing the synapomorphy of stomatal chamber openings being a narrow slit that hides the guard cells.

Sideroxylon tenax is primarily a coastal species. Tolerant of drought and salt, it inhabits sand dunes–not only the modern dunes of the Atlantic coastline, but also the ancient dunes of Florida’s interior upland sand ridges. S. tenax is also found, albeit less abundantly, in some of Florida's peninsular Gulf coast counties. Its association with current and former coastal sand dunes indicates that S. tenax originated as a coastal species. It is endemic to a relatively narrow range, including much of Florida, extending along the Atlantic coastline of Georgia and South Carolina, ranging sparingly into extreme southern coastal North Carolina. The species grows quite abundantly in upland scrub habitats throughout the ancient dunes of Florida's central peninsular sand ridges, from the Trail Ridge southwest of Jacksonville southward to the Lake Wales Ridge in

Polk and Highlands Counties. These ridges represent former coastlines during times of higher sea level during the past several million years. The inland Florida ridge variant of

S. tenax is morphologically distinct from plants of the modern coastlines. The trend on the inland ridges is toward darker-colored and less lustrous abaxial leaf pubescence,

smaller leaves, shorter pedicels, and perhaps a greater tendency to form stoloniferous clones. The variants intergrade over a wide area, therefore the inland variant cannot be recognized as a separate taxon. But this regional difference suggests that the inland populations have been isolated in the geological past from the coastal populations, when sea level rose high enough to inundate all but the central ridges of the Florida peninsula. Florida’s inland sand ridges, especially the southernmost Lake Wales Ridge, are a center of endemism (Ward 1979). The inland ridge variant of S. tenax is thus associated with the endemic-rich flora of the xeric scrub habitats of these areas (Huck et al. 1989; Corogin & Judd 2009).. In coastal areas, S. tenax thrives in open, sunny spaces in the zone between the pioneer dune vegetation and the forested maritime hammocks further inland. In the inland habitats, S. tenax grows scattered throughout the shrub layer of pyrogenic scrub dominated by Quercus spp., often with a scattered overstory of Pinus clausa (sand pine). In both coastal and inland areas, wherever the woody plant community grows to maturity, S. tenax is quickly overtopped by faster- growing species, persisting as a slow-growing small tree in the understory.

Sideroxylon alachuense is a narrow endemic of very restricted distribution. The largest population occurs in Alachua County, Florida, the namesake of the species, where it is restricted to the area near Alachua Sink in Payne’s Prairie State Park. The species also occurs sparingly at a few disjunct locations in Marion, Lake, and Orange

Counties, Florida. Morphology-based phylogenetic analysis (Chapter 3) groups S. alachuense and S. tenax together in a clade (the only subclade that received bootstrap support in the analysis), sharing the apomorphies of abaxial leaf epidermis of older leaves always obscured by pubescence, as well as similarities in the structure of the

stomatal chamber dome complexes. Even a casual glance at the abaxial leaf indumentum of the two species suggests an obvious close relationship—the pubescence is dense, and the trichomes are appressed, multi-layered, and co-oriented, presenting a silky, lustrous appearance. But the two species are quite different in their habitat preferences. Sideroxylon tenax grows in deep, well-drained sandy soils and xeric conditions, in association with xeric-adapted coastal dune or scrub species.

Sideroxylon alachuense, on the other hand, is associated with mesic hardwood forest species. The site of its principal population features mesic hardwood hammock on rolling sinkhole terrain with limestone outcrops, and an ecotone between forested hammock and open prairie. Sideroxylon alachuense occurs as scattered small trees in the forest understory, and along forest edges and old fencerows where the forest grades into open prairie. In contrast to the xeric and pyrogenic dune and scrub habitats of S. tenax, the mesic hardwood forest habitat of S. alachuense is not pyrogenic, and it features a microclimate humid enough to allow for an often prolific growth of epiphytic mosses and lichens on the twigs and branches of the species. This radically different habitat preference for two closely related species suggests that the species have differentiated ecologically. It is interesting to note that the more distantly related S. reclinatum subsp. reclinatum co-occurs with S. alachuense in the calcareous mesic hammock at Payne’s Prairie State Park, the plants sometimes growing side-by-side.

The remaining three species in the section are S. reclinatum (subspp. reclinatum and austrofloridense), S. rufohirtum, and S. macrocarpum. Morphological phylogenetic analysis (Chapter 3) indicates that these three species are closely related, forming a clade, the Sideroxylon reclinatum complex. Within this clade are two subclades. One

subclade contains S. rufohirtum and S. macrocarpum as sister species; the other subclade contains both subspecies of S. reclinatum.

The subclade of Sideroxylon reclinatum (both subspecies) includes plants primarily of Florida and the Gulf coastal plain, endemic to an area encompassing all of

Florida, and a few counties in southern Georgia and Alabama, and infrequently collected as far west as Louisiana. A mostly low-growing shrub (height typically 1–3 m), this species prefers wet to mesic habitats featuring sandy or clayey soils, often with limestone near the surface, usually associated with hardwood species. Sideroxylon reclinatum subsp. reclinatum, a glabrous plant of generally low stature with small leaves, is the more widespread of the two subspecies, its range being the range of the species, except for the extreme southern tip of the Florida peninsula. It is found in habitats with sandy soils, often with limestone near the surface, and usually associated with temperate hardwood species.

Sideroxylon reclinatum subsp. austrofloridense, on the other hand, is a narrow endemic taxon, found only in Miami-Dade, Monroe, and Collier Counties, Florida, where it is restricted to pine rocklands, marl prairies, and the edges of tropical rockland hardwood hammocks, associated with tropical hardwood species. These habitats feature exposed limestone overlain with a very thin layer of clayey marl soil. The southern tip of peninsular Florida, including the Florida Keys, is one of the state's hotspots of rare and endemic plant taxa (Ward 1979; Chaplin et al. 2000). Unusual for the continental United States, the flora of this region is dominated by tropical species of

West Indian origin. For a list of associated species, see Corogin & Judd (2014). The range of S. reclinatum subsp. austrofloridense (see Chapter 5) is centered in Miami-

Dade County on the Miami rock ridge, which extends from Long Pine Key in the

Everglades northward through urban Miami to the Miami River. The taxon is locally abundant at Long Pine Key, and is found at Pine Island, and around the edges of Royal

Palm Hammock and Paradise Key, in Everglades National Park. It has been collected in several extant rockland fragments in the urbanized areas of the Miami rock ridge as far north as the Miami City Cemetery. Historically, it was collected as far south as Key

Largo and Flamingo in Monroe County. More recently it has been collected farther west and north at locations in Big Cypress National Preserve: Monument Lake in Collier

County, and the Loop Road and Lostman's Pines areas in Monroe County (Hodges &

Bradley 2006; Gann et al. 2014). There are unvouchered reports of additional occurrences on the Miami rock ridge and in Big Cypress National Preserve (Gann et al.

2014). All locations where S. reclinatum subsp. austrofloridense has been collected have limestone bedrock either exposed at the surface or covered with only a thin layer of marl-based soil. These soils become more sandy toward the northwestern limits of the range, where S. reclinatum subsp. reclinatum is also found. Recent study (Corogin

& Judd 2014), utilizing scanning electron microscopy (SEM), along with close examination of specimens including more recent collections, and extensive field observations of both subspecies, reveal that the two subspecies are most reliably distinguished by differences in the micromorphology of the abaxial leaf epidermis (see

Chapter 5). The two subspecies are also separated eco-geographically. The more widespread subsp. reclinatum ranges as far south as Broward County in the east, and

Collier and Monroe Counties in the west, and its habitats feature sandy soils often with limestone near the surface, and temperate woody associate species. Subspecies

austrofloridense, on the other hand, is restricted to subtropical rockland and marl prairie habitats in a well-defined area of extreme southeast peninsular Florida, and its habitats feature exposed limestone, or limestone thinly overlain with clayey marl soils, and tropical woody associate species. The two subspecies, while quite similar in overall appearance, are thus clearly defined, and essentially allopatric.

Sideroxylon reclinatum subsp. austrofloridense is a taxon of conservation interest. It is a candidate for federal listing under the Endangered Species Act, under the common name "Everglades Bully" (USFWS 2013a). The pine rockland plant community where this plant grows is ranked critically imperiled both globally and in

Florida by the Florida Natural Areas Inventory (FNAI 2010). These pine rocklands once extended from Long Pine Key, the principal upland of Everglades National Park, northeastward along the Miami rock ridge as far as the Miami River, but urban and agricultural development has extirpated the native plant cover from all but Long Pine

Key and a handful of small patches on private land or preserved as county parks

(Olmsted et al. 1983; Bradley & Martin 2012). The chief immediate threats to

Sideroxylon reclinatum subsp. austrofloridense and its habitat are fire suppression and exotic species invasion. Recommended conservation actions currently consist of habitat protection and maintenance by prescribed fire, control of invasive non-native species, efforts to acquire, monitor and protect remaining rockland fragments, and continued monitoring and study to watch for adverse effects that may arise from human activities such as water management policies and the Everglades restoration program (Gann et al. 2002; FNAI 2010; USFWS 2013b). Long-term sea level rise due to climate change also threatens the rockland flora. Discovery of 8600-year-old submerged remains of

pine trees 60 km west of Key West suggests that since the last glacial maximum (ca.

18,000 years before present), south Florida pinelands have been in retreat as rising seas have inundated a once more extensive range; during the past century that retreat has continued measurably in the Florida keys (Ross et al. 1994, 2009). As sea level rises, outright inundation is preceded by saltwater intrusion, which is currently producing changes to the species composition of vulnerable south Florida coastal habitats (Saha et al. 2011). Sea level is predicted to rise 1–2 m by 2100 (URS Corporation et al. 2007;

Saha et al. 2011), and elevation at Long Pine Key is 2 m or less. Sideroxylon reclinatum subsp. austrofloridense and its rare and endemic associates clearly face an uncertain future.

The other subclade in the S. reclinatum complex, containing S. rufohirtum and S. macrocarpum, differs from the S. reclinatum subclade in two major ways. First, while S. reclinatum is a plant of wet to mesic habitats, often with limestone near the surface, S. rufohirtum and S. macrocarpum inhabit dry, pyrogenic upland habitats with deep, well- drained sandy soils. Second, while S. reclinatum occurs as individually isolated shrubs or small trees reaching a height of 1–3 m, S. rufohirtum and S. macrocarpum are highly clonal, forming often extensive patches of underground root and stem systems, with above-ground shoots usually less than 1 m tall. This growth habit, with most of the woody biomass below the soil or leaf litter surface, is likely an adaptation to the relatively frequent periodic fires (occurring every 1–10 years) typical of the pine- dominated sandhill habitats where these species are found.

Sideroxylon rufohirtum is endemic to Florida, found in well-drained sandy pyrogenic upland pine habitats in 17 counties of north, central, and western peninsula.

Sideroxylon rufohirtum is also sometimes found thriving along power line rights-of-way and road shoulders, where regular mowing (instead of fire) apparently favors the low- growing plant over its taller competitors. Godfrey (1988) pointed out, and I have observed, that plants of S. rufohirtum do not appear to be particularly common even in habitats where one would expect to find them, and they are often difficult to spot in the field.

Sideroxylon macrocarpum is endemic to Georgia, found only in 13 counties in the southeastern coastal plain portion of the state. The range of S. macrocarpum is located almost wholly within the Vidalia Upland physiographic district, which is characterized by rolling terrain with well-drained, often gravelly, sandy soils with clay present (Clark &

Zisa 1976). The species occurs in pyrogenic, dry to mesic oak-pine woodlands.

Sideroxylon macrocarpum also seems to thrive along power line rights-of-way and road shoulders, where regular mowing, instead of fire, apparently favors it over its taller competitors (Allison 2006). This species is listed as rare by the Georgia Department of

Natural Resources (Chafin 2008).

Sideroxylon rufohirtum and S. macrocarpum share similarities of habit, habitat and morphology; both prefer dry upland habitats with deep sandy soils, both are highly clonal and low-growing, rarely exceeding 1m in height, and they have comparatively large fruits (> 10 mm diameter), young stems pubescent through at least part of the first season, and abaxial leaf pubescence that is sparse and often persistent. However, the ranges of S. rufohirtum and S. macrocarpum are geographically separated by ca. 120 miles of lowlands, a basin that includes the Okefenokee Swamp, which has lacked suitable habitat for sandy upland plants since it was formed in the late Pliocene or early

Pleistocene, when sea level rose to cover the area (Cohen et al. 1984). Allison (2006) hypothesized that S. rufohirtum and S. macrocarpum may be sister species, the two species perhaps vacariantly separated by the evolution of the Okefenokee Swamp and associated lowlands. The low stature and clonal habit of these two species, likely an adaptation to fire, could also be due to convergent evolution. The sister species relationship of these two taxa is supported by morphological phylogenetic analysis

(Chapter 3).

The ranges of S. rufohirtum and S. macrocarpum are nested within the geographical range of the gopher tortoise, Gopherus polyphemus, an important seed- dispersing animal in pyrogenic sandy upland communities of the southeastern coastal plain (Auffenberg & Franz 1982; Diemer 1986). Allison (2006) speculated that the low stature and large fruit size of S. rufohirtum and S. macrocarpum suggest a possible coevolutionary relationship with the gopher tortoise.

The longleaf pine sandhill habitat of the southeastern United States comprises less than 3% of its original range (Condon & Putz 2007; Landers et al. 1995). Threats to this habitat, and therefore to S. rufohirtum and S. macrocarpum, are from fire suppression and conversion of the habitat to pine plantations, pastures and other human development (Chafin 2008).

Eco-Geographical Differentiation of the Species

When taxa tend not to co-occur in the same habitat with their closest relatives, the taxa are said to be phylogenetically overdispersed (Cavender-Bares et al. 2004a,

2004b). It seems clear from observations made for the present study that the phenomenon of phylogenetic overdispersion may account for the differentiation of at least some of the species of Sideroxylon section Frigoricola. In two subclades of the

section, it appears that closely related taxa have differentiated ecologically, becoming separated by specializing for different habitats. These subclades are the Sideroxylon tenax complex, i.e., S. tenax and S. alachuense, and the Sideroxylon reclinatum complex, i.e., S. reclinatum (subspp. reclinatum and austrofloridense), S. rufohirtum, and S. macrocarpum.

In the future, to test the hypothesis that the species of Sideroxylon section

Frigoricola are ecologically differentiated, a principal-components analysis can be performed, using presence/absence data for associated woody species found with a given Sideroxylon species at a given location. Several locations would be sampled for each of the species in the section. The data would be analyzed using ordination software such as MVSP (Kovach Computing Services, Anglesey, Wales, UK) or PC-

ORD (McCune & Mefford 1997).

Figure 4-1. Geographical ranges of the species of Sideroxylon section Frigoricola.

CHAPTER 5 TAXONOMY

Sideroxylon Linnaeus [Hort. Cliff. 69. 1737] Sp. Pl. 192. 1753. TYPE: Sideroxylon inerme L.

Bumelia Swartz, Prodr. 49. 1788. TYPE: Bumelia retusa Swartz [= Sideroxylon americanum (Miller) Pennington].

Argania Roemer & Schultes, Syst. Veg. 4: XLVI, 502. 1819. TYPE: Argania sideroxylon Roemer & Schultes, nom. illegit. [Argania spinosa (L.) Skeels (Sideroxylon spinosum L.)].

Spondogona Rafinesque, Sylva Tellur. 35. 1838. TYPE: Spondogona nitida Rafinesque [Bumelia pentagona Swartz (= Sideroxylon salicifolium (L.) Lam.]

Dipholis A. de Candolle in A.P. de Candolle, Prodr. 8:188. 1844. TYPE: Dipholis salicifolia (Linnaeus) A. de Candolle [Achras salicifolia Linnaeus (= Sideroxylon salicifolium (L.) Lam.)].

Sideroxylon sect. Mastichodendron Engler, Bot. Jahrb. Syst. 12:518. 1890. Mastichodendron(Engler) Lam, Recueil Trav. Bot. Neerl. 35:521. 1939; Cronquist, Lloydia 9:245. 1946. TYPE: Sideroxylon foetidissimum Jacquin (lectotype, Baehni 1965).

Bumelia subgen. Bumeliopsis Urban, Symb. Antill. 5:148. 1904. Bumelia sect. Bumeliopsis (Urban) Dubard, Ann. Inst. Bot.-Geol. Colon. Marseille ser. 2, 10:1. 1912. TYPE: Bumelia picardae Urban [= Sideroxylon picardae (Urb.) T.D. Penn.].

Bumelia sect. Bumeliopsis (Urban) Dubard, Ann. Inst. Bot.-Geol. Colon. Marseille ser. 2, 10:1. 1912.

Dipholis subgen. Pseudodipholis Urban, Symb. Antill. 7:325. 1912. TYPE: Dipholis anomala Urban (lectotype, T.D. Pennington 1990).

Apterygia Baehni, Arch. Sci. 17:79. 1964; Arch. Sci. 18:36. 1965. TYPE: Apterygia sartorum (Martius) Baehni (Bumelia sartorum Martius).

For a complete synonymy see Pennington (1991).

Trees or shrubs, armed with thorns or unarmed. Stipules absent. Leaves spirally arranged, or sometimes opposite, often becoming fascicled on brachyblasts (short shoots). Venation variable. Inflorescence sessile or rarely pedunculate, axillary or in the

axils of fallen leaves. Flowers solitary or fasciculate, usually perfect, rarely imperfect.

Calyx a single whorl of 5 (–8) quincuncial, free sepals. Corolla cyathiform, sympetalous, usually glabrous, tube almost always shorter than the lobes, rarely equaling or exceeding them; lobes (4–) 5 (–8), imbricate or quincuncial, spreading, entire or divided into a larger median lobe and two smaller lateral segments. Stamens (4–) 5 (–8), in a single whorl fixed at the top of the corolla tube, exserted; filaments well developed; anthers extrorse, usually glabrous; stamens sometimes converted into staminodes in staminate flowers. Staminodes (4–) 5 (–8), usually well-developed, petaloid, alternating with the stamens, often lanceolate, erose, infolded and incurved against the style, usually glabrous. Ovary (1–) 5 (–8)-locular, pubescent or glabrous; placentation basi- ventral or basal; style exserted or included. Fruit a berry, 1 (–2)-seeded, fleshy, usually glabrous. Seed globose, ovoid, oblong, or ellipsoid, not laterally compressed, rarely plano-convex when 2 seeds in a fruit; testa smooth, glossy, free from the pericarp, often thick and woody, often sculptured on the adaxial surface with several prominent thickened plates; hilum scar nearly always basal or basi-ventral, small, circular, lanceolate, or elliptic, sometimes bipartite, rarely adaxial and then broad. Embryo vertical, oblique, or horizontal, with thin foliaceous cotyledons and copious endosperm, or with plano-convex cotyledons and then with a thin sheath of endosperm or endosperm lacking; radicle exserted.

Distribution. Pantropical; ca. 80 species, occurring most abundantly in Central

America and the Caribbean, but also in Macaronesia, Africa, Madagascar, and the

Mascarene Islands, with very few in southeast Asia (Govaerts et al 2001). Eleven species occur in the warm-temperate southern United States.

Nomenclatural note. Pennington (1990) listed the name Auzuba Plumier ex

Jussieu in Lamarck in the synonymy of Sideroxylon in his monograph of Neotropical species, but he omitted it without comment in his monograph of the genus worldwide

(Pennington 1991). Lamarck (1811) attributes the name to unpublished works of

Plumier, stating that it refers to a tree of the West Indies with the common name

“acomat”, and that Plumier’s vague description seems close to Sideroxylon. Auzuba probably actually refers to Sloanea caribaea Krug & Urb. ex Duss (Elaeocarpaceae), called “acomat boucan”.

Discussion. Generic delimitation in Sapotaceae has been problematic because characters chosen to diagnose one group tend to overlap with those diagnosing another. This polythetic variation in the few morphological characters that have been considered useful at the “generic level” has led to widely differing circumscriptions and a confusing synonymy, with some species now having up to ten generic synonyms

(Pennington 1990, 1991). Illustrative of this problem were the publications of two discordant monographs of the family, one by Aubreville (1964), recognizing 125 genera, and another by Baehni (1965), recognizing only 63 genera. Prior to Pennington’s monographs of the Sapotaceae (1990, 1991), the species of the current genus

Sideroxylon were split among several genera. The Neotropical species of Sideroxylon, centered in the Caribbean and Central America and extending into the temperate southeastern U.S., were split among the genera Bumelia Sw., Dipholis A.DC., and

Mastichodendron (Engl.) H.J. Lam. They are trees and shrubs of mainly dry habitats, armed with thorns or unarmed, with leaves alternate to subopposite, often becoming fascicled on short shoots (brachyblasts), inflorescences fasciculate, axillary or in axils of

fallen leaves, flowers with a single whorl of quincuncial sepals, corolla lobes entire or often divided into a median segment and two lateral segments, petaloid staminodes alternating with epipetalous stamens, seeds with thin cotyledons and copious endosperm, or with fleshy cotyledons and endosperm scanty or lacking, the hilum scar unipartite or bipartite and in a basal position (Cronquist 1945). The species endemic to the continental United States (and extreme northern Mexico) were assigned to Bumelia, along with many tropical taxa (Cronquist 1945, 1946, 1949). Bumelia was revised by

Gray (1886), Small (1900), Clark (1942), and Cronquist (1945, 1949), all of whom differed concerning the number of U.S. species. Pennington (1990) found no sound morphological basis on which to delimit these genera, and he transferred all of Bumelia,

Dipholis, and Mastichodendron to a broadly circumscribed Sideroxylon. For species limits he generally followed Cronquist, recognizing eight species in the United States.

More recently, phylogenetic analyses using both morphological and molecular data have shown that Sideroxylon sensu Pennington is monophyletic including Argania from

Morocco (Anderberg & Swenson 2003; Swenson & Anderberg 2005; Smedmark et al.

2006), but excluding two taxa from the Arabian peninsula and Socotra (Smedmark &

Anderberg 2007; Gautier et al. 2013; Stride et al. 2014). Although relationships among the major subclades of Sideroxylon are currently unclear, molecular phylogenies reveal two well-supported Neotropical subclades, one corresponding to

Dipholis/Mastichodendron, and the other to Bumelia, including the species endemic to

North America (Smedmark & Anderberg 2007; Stride et al. 2014). Taxa in the Bumelia clade have been diagnosed morphologically from their relatives in Dipholis and

Mastichodendron by usually being armed with thorns, having pubescent ovaries, and

seeds with fleshy cotyledons, endosperm scanty or lacking (versus usually unarmed, ovaries glabrous, and seeds with thin cotyledons and copious endosperm). As mentioned above, exceptions to these character state differences are numerous enough to make morphological delimitation of Bumelia problematic (Pennington 1991). Further molecular study of these clades with more thorough taxon sampling may confirm their monophyly, and could allow recognition of Bumelia as a subgenus. (For a more detailed taxonomic history of Sideroxylon, see Pennington, 1991).

Currently eleven species of Sideroxylon are recognized in the continental United

States (Govaerts et al. 2001; Allison 2006; Wunderlin & Hansen 2008). Of these eleven species, eight are endemic to an area encompassing much of the southeastern United

States and the northern tier of states in Mexico, most of these species being concentrated on the coastal plain from Texas through the Carolinas, with Florida as their center of diversity (Govaerts et al. 2001; Allison 2006; Wunderlin & Hansen 2008).

These eight are Sideroxylon alachuense L.C. Anderson, S. lanuginosum Michx., S. lycioides L., S. macrocarpum (Nutt.) J.R. Allison, S. reclinatum Michx., S. rufohirtum

Herring & Judd, S. tenax L., and S. thornei (Cronquist) T.D. Penn. Morphologically, these taxa are distinguished from their tropical congeners by having a combination of fascicled leaves, conspicuously reticulate tertiary venation, short styles, small fruits, and a bipartite hilum scar (Chapter 3; Pennington 1990). Recent molecular analyses that sampled four of these taxa (Smedmark & Anderberg 2007; Stride et al. 2014) have suggested that they might form a monophyletic group, a supposition confirmed by the present study, which has sampled all eight species (see Chapter 2). To this morphologically distinctive group of eight species, forming a monophyletic group within

the Bumelia clade that has radiated into temperate southeastern North America, I here give the name Sideroxylon section Frigoricola.

Sideroxylon sect. Frigoricola Corogin, sect. nov. TYPE: Sideroxylon tenax L.

Trees or shrubs, nearly always armed with thorns; leaves always fascicled on brachyblasts on older stems, tertiary vein reticulum conspicuous adaxially, marginal vein absent, top portions of T-shaped trichomes of abaxial leaf indumentum greater than 0.6 mm long, stomata enclosed within dome-like chambers whose openings are elevated above surrounding cuticular surface; style always less than 2.5 mm long; seeds with bipartite hilum scar.

Shrubs or small trees to 20 m tall, usually armed with thorns (at least on younger branches), trunk diameter to 36 cm, the bark of mature trunks brown to grey, divided by longitudinal and sometimes also transverse fissures, the fissures often revealing orange-brown color of fresher bark, plants slightly to strongly stoloniferous. Indumentum of unicellular T-shaped trichomes, symmetric or asymmetric, terete and hollow to flattened in cross-section, having a short stalk 0.01–0.2 mm long, and a longer top portion 0.2–2 mm long, the top portion straight to bent to curled, appressed to ascending. Vegetative buds densely to sparsely pubescent, the trichomes short, brownish, appressed to ascending. Young twigs glabrous or pubescent, twig surface prominently dotted with lenticels; thorns often present at nodes, 0.2–4 (–10) cm long, thorns sometimes becoming brachyblasts (short spur shoots) or lengthening to become side branches. Mature twigs becoming glabrous after first or second season, the surface light tan to grey to brown, longitudinal and sometimes also transverse fissures often appearing with age, twigs bearing brachyblasts at nodes, which after many

seasons will occasionally lengthen into long shoots; internode length 0.5–4.5 cm.

Leaves tardily deciduous (fully deciduous in the colder parts of the species range), alternate and spirally arranged on young long shoots, becoming fascicled on brachyblasts on older stems, petioles 1–16 mm long, the petioles canaliculate and glabrous or pubescent; leaf blades highly variable in size, ranging from 1–15 cm long,

0.2–6 cm wide, narrowly to broadly obovate to elliptic, sometimes rhombic or suborbicular, rarely ovate, often larger on young long shoots than on short shoots, coriaceous, the apex acute to rounded to occasionally retuse, the base acute to cuneate, the margins entire and sometimes slightly revolute, blades flat to involute to slightly V-infolded along midvein; venation pinnate and visibly finely reticulate, major secondaries brochidodromous, or eucamptodromous becoming brochidodromous distally, with secondary veins slightly decurrent, branching off midvein in opposite to alternate arrangement, ± in 3–16 irregularly spaced pairs, with an intersecondary vein occasionally occurring between secondaries, the tertiary veins irregular-reticulate, the quaternary veins irregular-reticulate (or irregular-reticulate to freely ramifying if quinternary veins absent), the quinternary veins irregular-reticulate to freely ramifying, areolation moderately developed, the marginal ultimate venation looped; adaxial surface green, glossy to dull, glabrous, or pubescent when young and becoming glabrous, the major veins prominent, the higher-order vein reticulum evident to boldly conspicuous, the veins impressed to flush (often raised on dried specimens); abaxial surface glabrous, or with indumentum varying from moderately densely, evenly, and persistently pubescent to glabrate, the pubescence loosely wooly to sericeous to sericeous- tomentulose, the color dark to light brown, red-brown, grey, white, or colorless-

transparent, the T-shaped trichomes mostly terete or flattened in cross-section, the stalk

0.1–0.25 mm long, the upper portion 0.2–2 mm long, the upper portions straight to bent or curled, appressed to ascending, the leaf surface visible or obscured by pubescence, most veins evident, raised, the midvein and secondaries prominent, the higher order veins sometimes obscured by pubescence; stomata recessed inside dome-like chambers usually raised slightly from leaf surface, the base of the dome sometimes neatly bordered by one or two narrow cuticular ridges, the chamber openings wide and elliptical with the guard cells visible through the opening, or closed to a narrow slit and the guard cells not visible, each opening often surrounded by a ± well-developed complex of irregularly concentric cuticular ridges, often also with ridges radiating out perpendicular to the opening, the surface between stomata smooth and irregularly undulating to patterned in low to strong relief with grooves and ridges, epidermal cell boundaries obscure to evident, marked, if visible, by an impressed groove or by a raised ridge with or without an impressed groove along its middle. Inflorescence a fascicle borne in a leaf axil, several fascicles often tightly clustered on short spur shoots in axils of fallen leaves, each fascicle having ca. 2– 20 pedicellate flowers, the pedicels 2–12 (–

17) mm long, glabrous to persistently pubescent. Flowers 5 (–6)-merous; calyx of 5 (–6) quincuncial, free sepals, the outer two sepals 1.1–3 mm long, 1.8–3 mm wide, ovate to suborbicular (occasionally reniform), the apex rounded, rarely acute, the margin entire, usually with a narrow membranous rim, the inner three sepals 1.2–3 mm long, 1.5–3 mm wide, ovate to suborbicular (occasionally reniform), the apex rounded to retuse, the margin entire to erose, with a broad membranous rim, sepals glabrous to persistently pubescent. Corolla white, cyathiform, sympetalous, the tube 1–2.5 mm long, enclosed

within the calyx; the lobes 5 (–6), exserted and spreading, glabrous, each with a median lobe and two lateral segments, the median lobe 1.2–2.3 mm long, 1–2 mm wide, oval to suborbicular, clawed, cupped around a stamen, the lateral segments 1–2.3 mm long

(from junction with tube), 1.5–3 mm long (from junction with median lobe), 0.5–1.5 mm wide, lanceolate, all corolla margins erose. Stamens 5 (–6), epipetalous, opposite the corolla lobes, exserted; filament (0.8–) 1.1–2.5 mm long, 0.4 mm wide, fixed at top of corolla tube, dilated proximally and narrowing toward anther attachment; anther 0.9–1.6 mm long, ca. 0.5 mm wide, sagittate, ventrifixed near the point of the sinus, extrorse, opening by two longitudinal slits. Staminodes petaloid, alternating with stamens, each staminode 1.4–2.6 mm long, sometimes reaching less than 2/3 the length of the median corolla lobe, or most often nearly equaling the median corolla lobes and then usually exceeding the lateral segments, 0.7–1.9 mm wide, deltoid to ovate to lanceolate, infolded, base often slightly reflexed, margin erose. Ovary superior, 5 (–6)-loculate, locules uniovulate with basal-axile placentation, ovary ca. 0.8–1.4 mm long, 0.7–1.3 mm wide, globose to ovoid, tapering abruptly (or sometimes gradually) to the style, the ovary at anthesis glabrous to persistently pubescent with indumentum of straight, appressed trichomes, the trichomes often longer on distal part of ovary; style 0.9–1.8 mm long, glabrous, included. Fruit a berry, one-(rarely 2)-seeded, 6–15 mm long, 6–14 mm wide, obovoid to ellipsoid to subglobose, often tipped by a persistent style, black, glossy, glabrous. Seeds 4.0–13 mm long, 3.2–8.9 mm wide, subglobose to ellipsoid, the testa hard, smooth, glossy, the color dark to light brown to yellow-brown, solid to variegated; the hilum scar basal, usually bipartite, one part containing the funiculus and usually larger, of variable size and shape, suborbicular to oval to deltoid to roughly half-moon

shaped, 0.7–3.2 mm long, 0.7–3 mm wide, and a smaller, laterally elongate part abaxial to the other part, straight to curved to shallowly V-shaped, 0.2–4 mm long, 0.1–2.8 mm wide, the two parts separated by a bridge of testa or occasionally running together, the scar being the exposed portion of a hollow cavity under the testa extending a small distance around the basal end of the seed, the cavity filled, especially on the abaxial side, with a yellowish fatty substance.

Phenology. Flowering April–August, fruit ripening July–November.

Pollination. I have observed that flowers of species of Sideroxylon sect.

Frigoricola are visited by a wide variety of insects, mostly bees and wasps

(Hymenoptera), but also flies (Diptera), beetles (Coleoptera), and even butterflies

(Lepidoptera). Flowers in the genus Sideroxylon do not have a nectar disk (Pennington

1990, 1991), and I have not observed nectar present in flowers. But the fleshy texture and slightly sweet taste of the corolla tissue suggests that perhaps the corolla itself is the reward attracting so many typically nectar-seeking insects (Pennington 1990).

Fruit dispersal. In Sideroxylon sect. Frigoricola, the small size and purple-black color of the fruits suggests they are probably dispersed by birds. Fruits of the two low- growing species that occur in pyrogenic sandy uplands, i.e., S. rufohirtum and S. macrocarpum, may also be dispersed by the gopher tortoise, Gopherus polyphemus, known to be an important disperser of fruits of other plant species in these sandhill habitats (Auffenberg & Franz 1982; Diemer 1986; Allison 2006).

Chromosome numbers. Sideroxylon lanuginosum is the only species of

Sideroxylon sect. Frigoricola for which a chromosome count is reported. For this species, 2n=24, x=12 (Brown & Clark 1940). The few other species of Sideroxylon that

have been counted have 2n=24, or 2n=22; the most common counts reported for the family Sapotaceae are based on x=12, x=13, and x=14, with polyploidy being extremely rare (Johnson 1991).

Etymology. Frigoricola, from the Latin frigus, frigoris (cold weather, frost), and - cola (-dweller), an apt name for a monophyletic group of species tolerant of temperate- zone winter conditions within an otherwise tropical genus.

Common names. Buckthorn, bully, bumelia.

Distribution. Endemic to the southern United States, from southern Arizona through Texas, including extreme northern Mexico, north through Oklahoma, Kansas,

Missouri, and southern Illinois and Indiana, south through western Kentucky,

Tennessee, Arkansas and Louisiana, east through Mississippi, Alabama, Georgia, northern Florida, north through South Carolina, coastal North Carolina, southeastern

Virginia, and southern Delaware, with Florida as the center of diversity (Fig. 5-1).

Key to Species of Sideroxylon sect. Frigoricola

1. Abaxial leaf surface persistently pubescent ------2

2. Leaf pubescence dense, sericeous to sericeous-tomentulose, the trichomes appressed and co-oriented, leaf surface obscured by pubescence ------3

3. Young twigs densely pubescent; twig surface dark brown to red-brown; leaf pubescence golden to rusty brown ------3. S. tenax

3. Young twigs glabrous or with a few scattered, quickly deciduous pale trichomes; twig surface green to cream-white, becoming light grey; leaf pubescence silvery-white to very slightly golden ------4. S. alachuense

2. Leaf pubescence moderate to sparse, wooly, the trichomes ascending to appressed, not co-oriented, leaf surface visible, not obscured by pubescence - 4

4. Plants strongly stoloniferous; mature plants usually less than 1 m tall; fruit greater than 1 cm long ------5

5. Pubescence on young twigs dense, rusty dark red-brown, often persisting well past the first season; abaxial leaf pubescence rusty red-brown, sparse to moderately dense, often giving surface a distinctly reddish hue; staminodes nearly as long as median corolla lobes; ovary densely pubescent; seed variegated; stomatal chamber openings located on raised, donut-shaped platforms ------7. S. rufohirtum

5. Pubescence on young twigs moderate to dense, blonde to light brown, rarely persisting past the first season; abaxial leaf pubescence blonde to light brown, sparse,; staminodes only to 1/3 to 1/2 the length of median corolla lobes; ovary glabrous or with a few trichomes medially; seed uniformly brown; stomatal chamber openings atop ellipsoidal domes neatly bordered by one or more concentric cuticular ridges ------8. S. macrocarpum

4. Plants not strongly stoloniferous; mature plants often greater than 1 m tall; fruit usually less than 1 cm long ------6

6. Leaf vein reticulum conspicuous, highest-order veins quinternary; stomatal chamber openings wide and elliptic, guard cells visible through opening ------7

7. Young twigs glabrous or nearly so, and abaxial leaf pubescence finely wooly; plant growing in extreme southern peninsular Florida ------6. S. reclinatum (in part)

7. Young twigs densely pubescent, and abaxial leaf pubescence wooly; plant growing from central Florida north and west through southern USA and northern Mexico, but not in extreme southern peninsular Florida ------5. S. lanuginosum (in part)

6. Leaf vein reticulum evident but not boldly conspicuous, highest-order veins quaternary; stomatal chamber openings closed to a narrow slit, guard cells not visible through opening ------2. S. thornei

1. Abaxial leaf surface pubescent only when leaves very young, quickly becoming glabrous or glabrate ------8

8. Leaf trichomes colorless, transparent, often flattened in cross-section; stomatal chamber openings closed to a narrow slit, guard cells not visible through opening ------1. S. lycioides

8. Leaf trichomes pigmented or opaque, mostly terete in cross-section; stomatal chamber openings wide and elliptic, guard cells visible through opening ------9

9. Young twigs glabrous, or if pubescent, quickly becoming glabrous; plant of moist to wet places, growing in Florida and along Gulf coastal plain west to Louisiana ------6. S. reclinatum (in part)

9. Young twigs pubescent, pubescence persisting through first season; plant of dry places, growing from western Oklahoma and central Texas west to Arizona, northern Mexico ------5. S. lanuginosum (in part)

1. Sideroxylon lycioides L., Sp. Pl. ed. 2, 1:279. 1762. Sideroxylon spinosum Duham., Traite Arbr. Arbust. 2:260, pl. 68. 1755, non S. spinosum Linnaeus, Sp. Pl. 1:193 (1753). Sideroxylon lyciifolium Salisb., Prodr. Stirp. Chap. Allerton 139. 1796, nom. superfl. Bumelia lycioides (L.) Pers., Syn. Pl. 1:237. 1805. Bumelia lycioides (L.) Willd., Enum. Pl. 249. 1809. Decateles lycioides (L.) Raf., Sylva Tellur. 36. 1838. Lyciodes spinosum Kuntze, Revis. Gen. Pl. 2:406. 1891. TYPE: Without data (LECTOTYPE: LINN 261.6–internet image!). Lectotypified by Reveal, J.L. & C.E. Jarvis, Taxon 58:981. 2009.

Sideroxylon decandrum L., Mant. Pl. 1:48. 1767. Robertia decandra (L.) Scop., Intr. Hist. Nat.: 154. 1777. Decateles latifolia Raf., Sylva Tellur.: 36. 1838. TYPE: Without data, Kalm s.n. (LECTOTYPE: LINN 261.9–internet image!). Lectotypified by Reveal, J.L. & C.E. Jarvis, Taxon 58:981. 2009.

Sideroxylon laeve Walter, Fl. Carol.: 100. 1788. TYPE: USA. SOUTH CAROLINA: Without data, T. Walter s.n. (LECTOTYPE: GH #00075867–internet image!) Lectotypified by R.B. Clark, Ann. Missouri Bot. Gard. 29:170. 1942.

Bumelia ambigua Ten., Index Seminum [Naples (Neapolitano)] 1829:15. 1829. Bumelia ambigua Ten. ex A. DC., Prodr. (A.P. de Candolle) 8:189. 1844. TYPE: Not seen.

Bumelia cassinifolia Small, Bull. New York Bot. Gard. 1:442. 1900. TYPE: LOUISIANA. ST. LANDRY PARISH: Opelousas, 17 Aug 1883, G.W. Letterman 287 (HOLOTYPE: NY #00273368–internet image!).

Bumelia lucida Small, Bull. New York Bot. Gard. 1:443. 1900, non B. lucida Roem. & Schult., Syst. Veg., ed. 15 bis (Roemer & Schultes) 4:499 (1819). Bumelia smallii R.B. Clark, Ann. Missouri Bot. Gard. 29:172. 1942. TYPE: LOUISIANA: Feliciana, 1838, W.M. Carpenter 19 (LECTOTYPE: NY #00273372–internet image!). Lectotypified by R.B. Clark, Ann. Missouri Bot. Gard. 29:173. 1942.

Bumelia lycioides (L.) Pers. var. virginiana Fernald, Rhodora 38:439. 1936. TYPE: USA. VIRGINIA. PRINCESS ANNE CO.: Dry wooded slope near Third Street Bridge, Great Neck, 5 Sep 1935, M.L. Fernald & B. Long 4987 (HOLOTYPE: GH #00075486–internet image!; ISOTYPES: K #000777897–internet image!, NY #00273374–internet image!, PH–3 sheets–#00008672, #00008673, #00008674–internet images!).

Bumelia lycioides (L.) Pers. var. ellipsoidalis R.B. Clark, Ann. Missouri Bot. Gard. 29:172. 1942. TYPE: USA. TENNESSEE. DAVIDSON CO.: Nashville, July–Sep 1879, Gattinger s.n. (HOLOTYPE: MO? not seen).

Shrub or small tree to 14 m tall, trunk diameter to 35 cm, the bark of mature trunks grey-brown to light grey, divided by longitudinal and sometimes also transverse fissures, the fissures revealing orange-brown color of fresher bark, plants not strongly stoloniferous. Indumentum of unicellular, fine, transparent and colorless T-shaped trichomes, symmetric or asymmetric, terete and hollow to flattened in cross-section, having a short stalk and a longer top portion of varying length, the top portion usually straight, sometimes bent, rarely curled. Vegetative buds moderately to sparsely pubescent with short, blond to light brown T-shaped trichomes, the trichomes terete to flattened in cross-section, the top portions appressed to ascending. Young twigs (long shoots) terete, 1.5–2.0 mm wide, glabrous, or moderately to sparsely sericeous- tomentulose when very young and quickly becoming glabrous, the T-shaped trichomes

(when present) fine, colorless and transparent, terete to flattened in cross-section, with stalk 0.05–0.1 mm long, top portion 0.7–1.4 mm long, the top portions straight to bent, appressed to ascending, the twig surface green, becoming dark red-brown to gray- brown, prominently dotted with lenticels and developing short, fine longitudinal fissures that lengthen with age of twig; thorns often present at nodes, especially on younger stems, thorns 0.7–3 (–4) cm long, occasionally lengthening to become side branches.

Mature twigs glabrous, the surface dark brown to gray, prominently dotted with lenticels, with longitudinal fissures and often also short transverse fissures appearing with age, bearing short spur shoots (brachyblasts) at nodes, the brachyblasts reaching lengths of up to 1.8 cm on some older twigs, and occasionally breaking out of the short-internode

growth pattern to lengthen as long shoots; internode length 1–4 cm. Leaves tardily deciduous (fully deciduous in the colder parts of the species range), alternate and spirally arranged on young long shoots, becoming fascicled on brachyblasts on older stems, petioles 4–16 mm long, the petioles canaliculate and glabrous; leaf blades generally consistent in size and shape on a single plant, but highly variable throughout the species, often larger on young long shoots than on short shoots, 2–15 cm long, 1.3–

4.8 cm wide, elliptic (most frequently) to oblanceolate to obovate, occasionally ovate, coriaceous to chartaceous, the apex usually acuminate to acute, sometimes rounded, rarely retuse, the base cuneate to acute, the margin entire, blade flat; venation conspicuously finely reticulate, the primary venation pinnate, eucamptodromous becoming brochidodromous distally, secondary veins slightly decurrent, branching off midvein in opposite to alternate arrangement, ± in 6–16 irregularly spaced pairs, a secondary vein sometimes forking dichotomously at half the distance from midvein to margin, an intersecondary vein often occurring between secondaries, its length ca. 50% the distance between midvein and margin, its distal course reticulating, the tertiary and quaternary veins well-developed and irregular-reticulate, the quinternary veins irregular- reticulate to freely ramifying, areolation moderately developed, the marginal venation looped; adaxial surface green, dull to semi-glossy, often sparsely pubescent when very young with quickly deciduous, fine, appressed, pale trichomes, becoming glabrous, midvein and secondaries prominent, higher-order vein reticulum conspicuous, slightly impressed to flush with surface (fresh leaf) to conspicuously raised and bony- cartilaginous (dried leaf); abaxial surface dull, often moderately to sparsely sericeous- tomentulose when very young with fine, appressed, colorless, transparent T-shaped

trichomes, most trichomes flattened in cross-section (some terete), with stalk 0.01–0.05 mm long, top portion 0.5–1 (–1.4) mm long, most trichomes quickly deciduous, the mature surface glabrous but often retaining a sparse scattering of these trichomes, the vein reticulum conspicuous and raised; stomata (Fig. 5-2) recessed inside dome-like, ellipsoidal chambers raised slightly from the leaf surface, each chamber opening a narrow slit ca. 9–12 micrometers long, the guard cells not visible through the opening, each chamber dome neatly bordered by a single narrow cuticular ridge that forms a bead around the base of the dome, additional narrow cuticular ridges sometimes present, forming patterns extending radially from base of dome, the surface between stomatal complexes sometimes also patterned in low to strong relief with broad ridges roughly following epidermal cell boundaries. Inflorescence a fascicle borne in a leaf axil, several fascicles often tightly clustered on short spur shoots in axils of fallen leaves, each fascicle having ca. 4–20 pedicellate flowers, the pedicels 2–8 (–12) mm long, glabrous. Calyx of 5 (–6) quincuncial, free sepals, the outer two sepals 1.1–2.2 mm long, 1.2–1.8 mm wide, ovate to suborbicular, the apex rounded, the margin entire, with narrow membranous rim, the inner three sepals 1.7–2.3 mm long, 1.5–2.3 mm wide, ovate to suborbicular, the apex rounded, the margin entire to erose, with broad membranous rim, all sepals glabrous. Corolla white, cyathiform, sympetalous, the tube

1.2–1.5 mm long, enclosed within the calyx, the lobes 5 (–6), exserted and spreading, glabrous, each with a median lobe and two lateral segments, the median lobe 1.9–2.3 mm long, 1.2–1.7 mm wide, oval, clawed, cupped around a stamen, the lateral segments 1.5–2 mm long (from junction with tube), 1–1.5 mm long (from junction with median lobe), 0.5–0.8 mm wide, lanceolate, margins erose. Stamens 5 (–6),

epipetalous, opposite the corolla lobes, exserted; filament 1.5–2.5 mm long, 0.4 mm wide, fixed at top of corolla tube, dilated proximally and narrowing toward anther attachment; anther 1.1–1.6 mm long, sagittate, ventrifixed near the point of the sinus, extrorse, opening by two longitudinal slits. Staminodes petaloid, alternating with stamens, each staminode 1.8–2.4 mm long, nearly equaling the median corolla lobes and greatly exceeding the lateral segments, 1–2 mm wide, ovate to deltoid, infolded, base often slightly reflexed, margin erose. Ovary superior, 5– (6–) loculate, locules uniovulate with basal-axile placentation, ovary 0.9–1.1 mm long, 0.8–1.2 mm wide, subglobose, tapering abruptly to style, the ovary at anthesis nearly glabrous to sparsely strigose with pale, transparent trichomes, style 1.2–1.8 mm long, glabrous, included.

Fruit a single-seeded berry (rarely 2-seeded), 7–15 mm long, 6–12 mm wide, subglobose to ellipsoid to obovoid, black, glossy, glabrous. Seeds 6–10 mm long, 4–7.6 mm wide, ellipsoid to subglobose, the testa hard, smooth, glossy, the color solid light brown to yellow-brown, occasionally faintly variegated; the hilum scar basal, usually bipartite, one part containing the funiculus and usually larger, of variable size and shape, suborbicular to roughly half-moon shaped, 1.5–2.2 mm long, 1.4–2 mm wide, and a smaller, laterally elongate part abaxial to the other part, generally curved or shallowly V-shaped, 1.8–2 mm long, 0.5–1 mm wide, the two parts separated by a bridge of testa or occasionally running together, the scar being the exposed portion of a hollow cavity under the testa extending a small distance around the basal end of the seed, the cavity filled, especially on the abaxial side, with a yellowish fatty substance.

(See Fig. 5-3).

Distribution and habitat. Southeastern USA, from coastal counties of southern

Delaware, southeastern Virginia, and North Carolina, westward through South Carolina,

Georgia, Tennessee, western Kentucky, Alabama, Mississippi, Louisiana, and sparingly into southeastern Texas, Arkansas, southeastern Missouri, southern tips of Illinois and

Indiana, and northern Florida (Fig. 5-4). A plant primarily of moist to wet habitats, it is found along riverbanks and in wooded bottomlands and adjacent slopes and bluffs.

Phenology. Flowering Jun–Aug, fruit ripening Sep–Nov.

Common names. Gopherwood, buckthorn bully, southern buckthorn.

Illustrations. Elisens & Jones (2009, p. 236); Gaertner (1805, Pl. 202, Fig. 3);

Godfrey (1988, Fig. 319, by Melanie Darst); Jaume Saint-Hilaire (1832, Pl. 481); Nuttall

(1849, Pl. 91); Sargent (1893, Tab. 248).

Specimens examined. USA. Alabama. Barbour Co.: AL Hwy 95, ca. 0.4 mi S of US Hwy 431 and ca. ½ mi E of AL Hwy 95, T9N, R29E, Sec 5, 30 Nov 1992,

Diamond 8505 (AUA). Bibb Co.: Unnumbered dirt rd at Cahaba River, 2.7 mi E of AL 5, just S of AL 25W, center sec 29, T22N, R9E, ca. 7 mi S of Centreville, 16 Sep 1985,

Horn 943 (UNA). Blount Co.: SE facing slope of Red Mountain, 33°52’49”N,

86°34’4”W, 16 May 1998, Keener 800 (UNA). Bullock Co.: Un-numbered dirt rd ca. 1 mi W of Macon County line, 32°13’48”N, 85°52’21”W, 28 Aug 2005, Diamond 157010

(UNA). Butler Co.: Fence row along Butler County 15, 20 Aug 1970, Moore 778 (AUA).

Calhoun Co.: Ca. 2 mi W of US 431 off Ohatchee Rd, 8 Nov 1984, Whetstone 14740

(AUA). Colbert Co.: NW of Hatton on AL 157, 27 Aug 1969, Kral 36380 (FSU, GA,

OKL). Conecuh Co.: Without location data, 15 Jun 1941, Kelly 20 (A). Dallas Co.:

Banks of Alabama River, Selma, Jul 1900, Cocks s.n. (A). Escambia Co.: East

Brewton, Auburn University Agricultural Station, 10 May 1999, Searcy s.n. (AUA).

Franklin Co.: 0.8 mi N of AL 84, by Co. Rd 83, vicinity of Russellville, 5 Jun 1981,

Godfrey 78774 (FSU). Greene Co.: 1 mi N of Pleasant Ridge, grading into chalk outcrop, 13 Jun 1967. McDaniel 9240 (MISS). Hale Co.: Near Greensboro, 2 Sep 1986,

Clary s.n. (AUA). Houston Co.: Banks of the Chattahoochee River at Gordons Landing near Gordon, 22 Jun 1984, Whetstone 14241 (UNA). Jefferson Co.: Powderly, 15 Apr

1929, Palmer 35353 (A). Lawrence Co.: Limestone woods, 5 Oct 1940, Morgan s.n.

(AUA). Lowndes Co.: Blackbelt roadside, Letohatchee, 6 Jul 1967, Atkins s.n. (AUA).

Madison Co.: 0.3 mi W of Fearn Hill Driive, Monte Sano Mt., Huntsville, T3S, R1E, W half Sec 29, 10 Jul 1980, Meigs 1000 (UNA). Marengo Co.: On Hwy 53, 5 mi S of

Uniontown, 18 Jun 1969, Thomas 2248 (UNA). Morgan Co.: 2 air mi W of Laceys

Spring, NE tip of Walling Mountain near jct of Deaton Rd and AL Hwy 36, 34°31’57”N,

86°38’11”W, 15 Jun 2003, Keener 2593 (UNA). Pike Co.: Near Troy, 4 Jul 1880, Mohr

966 (UNA). Russell Co.: Along old secondary rd off AL Hwy 37, 1.6 mi S of Lee Co. line, 3 mi from Marvyn, 8 Jul 1981, Warlick 35 (AUA). Sumter Co.: Ca. 2 mi SW of where Hwy 11 crosses the Tombigbee River, E side of hwy, 24 Apr 1976, Wofford et al.

51945 (TENN). Tuscaloosa Co.: Near Lock 14, 20 Jun 1955, Patton s.n. (UNA).

Arkansas. Ashley Co.: Gilliam Slough W of AR 133 and 1.2 mi N of LA state line, Sec

27, T19S, R9W, Thomas & Hooks 93103 & 1109 (TENN). Bradley Co.: Warren, 22

May 1943, Demaree 24439 (GH). Crittenden Co.: Turrell, 25 Jul 1927, Demaree 3723

(USF). Hempstead Co.: Along Yellow Creek, near McNab, 27 Oct 1924, Palmer 26725

(A). Lafayette Co.: Near Posten Bayou ca. 2 mi N of LA-AR state line, 10 Jun 1976,

Montz 4259 (LSU). Montgomery Co.: Without location data, 24 Apr 1984, McKenzie

s.n. (AUA). Monroe Co.: Along White River at AR 1 bridge in White River National

Wildlife Refuge E of St. Charles, Sec 4, 2 Jul 2001, Thomas 170715 (TENN). Phillips

Co.: Crowley’s Ridge, near Helena, 26 May 1924, Palmer 25137 (GH). Delaware.

Sussex Co.: Cape Henlopen State Park, W of trail at point where it turns E of Herring

Pt., 8 Oct 1997, McAvoy 3175 (USCH). Florida. Gadsden Co.: W end of Satsuma Rd,

Chattahoochee, 18 Apr 1988, Hill 19204 (USF). Jackson Co.: Close to Apalachicola

River, S of US 90 hwy bridge, E of Sneads, 27 Jun 1981, Godfrey 78969 (FSU);

Limerock outcrop, S side, Marianna by US 90, 13 May 1977, Kral 60039b (USCH).

Jefferson Co.: Lake Miccosukee, 10 Jan 1955, Kurz 54355 (FSU). Lafayette Co.: S side of Suwannee River, just E of Troy Spring, ca. 1.5 air mi NW of Mt Paran Church, ca. 11 air mi ESE of jct of FL 51 and US 27 in Mayo; Troy Spring; O’Brien 7.5’ Quad;

NWQ, NEQ, SEQ, Sec 34, T5S, R13E, 30°00’23”N, 82°59’56”W, 7 Jul 1992, Orzell &

Bridges20024 (USF). Lake Co.: 2 mi N of Mt Plymouth, 24 Jun 1981, Daubenmire s.n.

(USF). Liberty Co.: Bank of Apalachicola River, downriver from properties of The

Nature Conservancy, N of Bristol, 18 May 1984, Godfrey 81322 (FLAS, FSU); natural levee along Apalachicola River, Bristol, 5 Oct 1949, Kurz s.n. (FSU). Marion Co.:

Mormon Branch, Ocala National Forest, along access rd E of FL 19, ca. 1.2 mi S of FL

19 bridge over Juniper Creek; Mormon Branch is a small stream that crosses rd ca. 0.5 mi E of FL 19, 6 Apr 1988, Judd 5581(FLAS). Orange Co.: Wekiwa Springs, 12 Aug

1929, O’Neill s.n. (US). Putnam Co.: Deep Creek, 0.4 mi E of FL Rt 315, ca 5 mi S of

Interlachen, 25 Nov 1984, Godfrey 81710 (FLAS, FSU); South of Palatka, 8.6 mi SW of intersection SR 17 and CR 100 to Hoot Owl Rd, follow Hoot Owl Rd S 0.47 mi to Robin

Dr, then 0.76 mi E to Hoot Owl gate, 0.55 mi SE of gate, 29.560199°N, 81.613759°W,

Herring 1551 (USF). Georgia. Catoosa Co.: Ringgold, 10 Aug 1895, J.K. Small s.n.

(US). Charlton Co.: St. Mary’s River, 1 May 1921, Harris C21149A (US). Cherokee

Co.: On terrace at edge of old field and tree line along bank of Etowah River, 5 mi WSW of Canton, 2 May 1948, Duncan 8204 (GA). Clarke Co.: Near banks of Middle Oconee

River just S of Tallassee Shoals, 27 Oct 1940, Duncan 3106 (FLAS, TENN). Dade Co.:

Side of canyon just inside mouth of Sutton’s Gulf, 19 May 1940, Duncan 2422 (GA).

DeKalb Co.: On Mount Panola, 24 Jul 1940, Matthews s.n. (GA). Dooly Co.: E bank of

Flint River, ca. 12 mi W of Vienna, 28 Oct 1939, Duncan 1872 (GA). Early Co.: Bluff of

Chattahoochee River, near Hilton, 26 Jun 1947, Thorne 4976 (GA). Elbert Co.:

Floodplain of the Savannah River, 34°14’45” N, 82°44’55”W, ca. 0.75 mi S of the GA

368 bridge over the Savannah River, 7 Jun 1979, Credle 865 (GA). Floyd Co.: 3 mi SW of Rome, 3 Oct 1952, Duncan 14191 (GA). Gordon Co.: E bank of Oothkalooga Creek,

2 mi S 9°E of Calhoun, 24 Sep 1948, Duncan 8946 (GA). Harris Co.: Along Standing

Boy Creek directly N of Columbus, 4 Jun 1949, Duncan 9667 (GA). Hart Co.: Steep hillside along the Tugaloo River ca. 1 mi ESE of the N end of Franklin-Hart Co. line, 24

Aug 1947, Duncan 7825a (GA). Heard Co.: Near Franklin, 27 Jun 1881, Ravenel s.n.

(GH). Houston Co.: Oaky Woods Wildlife Mgmt Area, ca. 2.75 air mi ESE of Kathleen,

UTM Zone 17, 0259179E, 3597076N, datum NAD83, 17 Oct 2004, Echols et al. 7 (GA).

Jasper Co.: Oconee National Forest, compartment 114, stand 2, Little Gladesville

Creek, near Forest Service Rd 1020, 13 May 2004, Kruse 04-62 (GA). Jeff Davis Co.:

Bullard Creek Wildlife Mgmt Area, along river, 31.95382°N, 82.48080°W, 2 May 2000,

Holland 482 (GA). Lincoln Co.: On Price’s Island in Savannah River, SE part of county,

29 Jun 1949, Duncan 9846 (GA). McDuffie Co.: SE of Aonia, Clark Hill Wildlife Mgmt

Area, large outcropping of rock which juts out into Clark Hill Lake, 19 May 1982, Coile

2795 (TENN). Oglethorpe Co.: On Echols Mill granitic outcrop, 9.3 mi N, 45° E of

Lexington, 21 Oct 1967, Blake & Montgomery 982 (FLAS). Putnam Co.: Rocky hillside overlooking Little River, 30 Apr 1942, Duncan 4912 (GA). Richmond Co.: Bank of

Savannah River at Sandbar Ferry, Augusta, 26 Apr, 23 May, 5 Aug 1900, Cuthbert s.n.

(FLAS). Stephens Co.: Along Tugaloo River just above jct with Toccoa Creek, 6 mi E

30°N of Toccoa, 18 Oct 1952, Duncan 14464 (GA). Stewart Co.: Bank of

Chattahoochee River, 19 Jul 1901, Harper 1100 (US). Walker Co.: W of LaFayette, E slope of Pigeon Mountain, beside Waterfall Branch, 18 Jul 1987, Coile 4755 (GA).

Walton Co.: Midway between Loganville and Walnut Grove, off Rabbit Farm Rd, 8 May

1983, Duncan 30859 (GA). Wilkes Co.: On large island in Broad River at Anthony

Shoals, 26 Aug 1939, Duncan 1609 (GA). Illinois. Alexander Co.: Cairo, 23 Apr 1919,

Palmer 14930 (A). Hardin Co.: Without location data, 12 Jun 1919, Palmer 15473 (US).

Pope Co.: Near Ohio River, Golconda, 17 Sep 1923, Palmer 23776 (A). Pulaski Co.:

Mound City, 1875, Wolf s.n. (US). Indiana. Perry Co.: Rocky bluff of Ohio River ca. 2 mi above Cannelton, 29 Jun 1915, Deam 16602 (A). Kentucky. Ballard Co.:

Mississippi River bottoms, Wickliffe, 15 Sep 1937, Anderson s.n. (GH). Crittenden Co.:

E bank of Cumberland River, 0.6 mi down private rd NW of old Pinckneyville-Dycusburg

Rd, WNW slopes on limestone, 30 May 1969, Browne 69E11.7 (TENN); Copperas

Spring Rd, 3.1 mi S of jct KY 120 in Tribune, 28 May 1976, Browne 76B11.3 (TENN).

Edmonson Co.: Mammoth Cave National Park, S bank of Green River, W of Turnhole

Bend and N of Brownsville Rd, 29 Jun 1963, Browne 7486 (TENN). Hart Co.: Bluffs of

Green River, 20 May 1940, Braun 3058 (A). Livingston Co.: Banks of Tennessee

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River, oxbow NE of George Rogers Clark Memorial Bridge off US 60, 11 May 1971,

Browne 71E4.2 (TENN). Logan Co.: KY 106, 1.1 mi E of jct KY 1151, S of highway, 27

May 1976, Browne 76B6.1 (TENN). Lyon Co.: Near Star Lime Works, 29 Jul 1936,

Shacklette 440-b (GH). Muhlenberg Co.: Central City, 4 Jun 1920, Palmer 17731 (A).

Warren Co.: Bowling Green, May 1895, Price s.n. (A). Louisiana. Acadia Parish:

Along railroad W of Esterwood, 26 Apr 1936, Brown 6287 (LSU). Allen Parish:

Between railroad and US 190, ca. 4 mi W of Kinder, 25 Jul 1981, Allen 11185 (LSU).

Assumption Parish: Beside LA 400 at a bayou ca. 7.2 mi W of LA 1 and Supreme,

Sec. 12, T14S, R13E, 23 May 1990, Thomas 117539 (TENN). Avoyeiles Parish:

Marksville, 12 Sep 1912, McAtee 2192 (US). Bossier Parish: Black Cypress

Recreation Area, 22 Apr 1983, Givens 3000 (LSU). Calcasieu Parish: Along Creek Rd in NW part of parish, ca. 1.5 mi from jct Big Woods Rd and just S of crossing of Houston

River, ca. 6 air mi W of Starks, T9S, R12W, S3, 17 Oct 1997, Mayfield & Neyland 2626

(LSU). Catahoula Parish: 0.5 mi E of Sicily Island, on gravel rd S lf LA 15, Sec 15,

T10N, R8E, 5 Jun 1970, Thomas 19089 (LSU). Concordia Parish: Railroad r/w E of

US 65, 1.5 mi M of LA 15 and Clayton, Sec 26, T9N, R9E, 7 Aug 1988, Thomas 106633

(TENN). East Baton Rough Parish: LSU Lake, 3 Jun 1899, Anders s.n. (LSU). East

Feliciana Parish: 5 mi ENE of Wilson, 6 Jul 1966, Thieret 24119 (A). Grant Parish:

Beside LA 500, 3.5 mi W of Georgetown, Sec 15, T9N, R1W, 5 Aug 1972, Thomas

31749 (GA). Iberville Parish: Vicinity of Spanish Lake, E of Sunshine, 29 Oct 1943,

Brown 9963 (LSU). Madison Parish: Tensas River National Wildlife Refuge, E of checkpoint, E of Cross Bayou, W of US 54, SW of Tallulah, Sec. 2, T14N, R11E, 27 Jul

1994, Thomas 140811 (GA). Morehouse Parish: NW ¼, Sec 24, T23N, R5E, S. of

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Irvine Lake, 25 Oct 1969, Thomas 17097 (GA). Orleans Parish: Without data, Apr

1846, Engelmann s.n. (GH). Ouachita Parish: Bank of Bayou DeSiard, E of US 165, N of Monroe and 1 mi S of LA 134, T19N, R4E, 23 Sep 1992, Thomas 130892 (TENN).

Plaquemines Parish: Between Nairn and Buras, 23 Dec 1948, Ewan 17981 (GH).

Rapides Parish: Alexandria, 1888, Hale s.n. (US). St. Charles Parish: Ca. 100 yds N of Illinois Central railroad near South Destrehan Ave, Destrehan, LA, 2 May 1980,

Montz 4990 (LSU). St. Helena Parish: Along Amite River 7.5 mi WSW of Pine Grove,

Sec. 47, T4S, R3E, 19 Jun 1971, Allen 1057 (LSU). St. Landry Parish: Opelousas, 11

Aug 1883, Letterman s.n. (A): TYPE of Bumelia cassinifolia Small. St. Mary Parish:

Vicinity of Jeanerette, without date, Casselman s.n. (LSU). Tensas Parish: Chicago

Mills Wildlife Mgmt Area, ca. 1 mi NE of Roaring Bayou bridge, Sec 31, T14N, R10E, 10

Oct 1980, Briley & Nixon 1965 (AUA). Terrebonne Parish: North of Houma, 28 Oct

1912, Small 912 (LSU). Union Parish: W bank of Ouachita River and edge of a slough at Ouachita City Landing N of LA 2 and Sterlington, Sec 16, T20N, R4E, 19 Sep 1997,

Thomas 155277 (TENN). West Carroll Parish: Without location data or date, Copes s.n. (LSU). West Feliciana Parish: Ca. 15 mi NNW of St Francisville, Sec 76, T1S,

R3W, 8 Aug 1972, Curry 341 (LSU); Magnolia Glen, Tunica Hills, LA Nature

Conservancy, 30°50’N, 91°30’W, Feb-Mar 1991, Quigley 156 (LSU). Winn

Parish:Roadside of LA 34 at branch of Bushy Creek, N of LA 499 and 1.6 mi N of US

84 at Joyce, Secs 4 & 5, T11N, R2W, 22 May 1999, Thomas 159984 (TENN).

Mississippi. Alcorn Co.: Facing Tuscumbia River bottom N of Buffalo Hole, ca. 4 mi W of Corinth, 7 Jun 1957, Ray & Cooley 5219 (USF). Chickasaw Co.: Ca. 2.5 mi N of Van

Fleet, T12S, R4E, S20, NW ¼, SE ¼, 8 May 1986, Stewart 2033 (MISS). Claiborne

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Co.: Bluffs NW of Lorman, 27 Apr 1978, Rogers 45122 (TENN). Clarke Co.: Bank of

Buckatunna Creek, 1 mi SE of Denham, 18 Jul 1956, Ray 7066 (USF). Forrest Co.:

Along Leaf River at McCallum, SE of Hattiesburg, 16 Sep 1966, Jones 10493 (GA).

Hinds Co.: South of Jackson, 28 May 1915, Harbison 95 (A). Jackson Co.:

Bottomlands of Pascagoula River, 10 Oct 1923, Ashe s.n. (FSU). Jefferson Co.: 7 mi

SW of Fayette, 9 Jun 1966, Jones 6370 (MISS). Jones Co.: Laurel, just N of jct

Tallahoma and Tallahala Creeks, NW4, S35, 2 Apr 1980, McDaniel 23450 (FSU). Lee

Co.: 3 mi W of Natchez Trace Pkwy (Tupelo), S side of MS Hwy 6, T10S, R5E, Sec 6,

SE ¼, 26 Jun 1999, Stewart 6644 (MISS). Leflore Co.: NW of Sidon, between Sidon cutoff and old Yazoo River run, T18N, R1E, Sec. 19, MSEA Project Area, Delta Region,

23 Apr 1999, Bryson 17103 (MISS). Lowndes Co.: Columbus, 16 Sep 1902, Biltmore

1689 (US). Noxubee Co.: Prairie draw, 2 mi E of Cliftonville, 3 Jul 1966, Marler 68

(MISS). Oktibbeha Co.: Botanical Garden of the South, ca. 1–1.5 mi S of Sessums,

Black Prairie region, E2, S27, T18N, R15E, 25 Sep 1993, Barton 113 (MISS). Perry

Co.: Bank of Leaf River N of New Augusta, 21 Jul 1967, Jones 14646 (FSU). Scott

Co.: Jackson Prairie, Harrel Prairie Hill, 3 mi SE of Forest along FS Rd 511, Bienville

National Forest, 20 Jun 1969, Jones 17040 (FLAS). Sharkey Co.: Twin Oaks Wildlife

Mgmt Area, ca. 5 mi S of Rolling Fork, T12N, R6W, S29, SW ¼, 20 Oct 1996,

MacDonald 9977 (MISS). Sunflower Co.: Ca. 8 mi NW of Drew, T24N, R4W, S22, SE

¼, 18 Jun 1988, Morris 3141 (FLAS). Warren Co.: Vicksburg, 2 Sep 1945, Demaree

25496 (GA). Washington Co.: NE of Stoneville, Delta Experimental Forest, T19N,R7W,

Sec 22, 29 Jun 1988, Morris 3202 (FLAS). Wilkinson Co.: Bluffs S of Ft. Adams, 22

Jun 1967, Jones 13516 (GA). Yazoo Co.: 4.5 mi S of Yazoo City near Short Creek, 23

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Aug 1958, McDaniel 1017 (USF). Missouri. Butler Co.: Neelyville, 3 Oct 1912, Sargent

6866 (A). Pemiscott Co.: Near Hayti, 23 Apr 1931, Palmer 39032 (US). North

Carolina. Brunswick Co.: Dunes SW of Long Beach, 15 Jul 1947, Fox 523 (GA,

TENN). Carteret Co.: Near Bogue Sound, Camp Glenn, S. of Morehead City, 30 Aug

1947, Fox 1107 (GH). Columbus Co.: North shore of Lake Waccamaw, 10 Jun 1958,

Bell 12838 (GA, USF). Craven Co.: Bank of Neuse River near mouth of Batchelder

Creek, 1.5 mi N of New Bern, 31 Aug 1947, Fox & Whitford 1126 (GH). Currituck Co.:

Church’s Island, Currituck Sound, 10 Jun 1949, Fox & Godfrey 2302 (GH). Dare Co.:

Behind low dunes, W of freshwater pond, Nags Head, 29 Jun 1947, Fox 380 (GA).

Jones Co.: Maysville, Aug 1932, Anon. s.n. (TENN). New Hanover Co.: Near

Wrightsville, 16 Jul 1897, Biltmore 1689a (GH). Onslow Co.: Bear Island or Hammock’s

Beach State Park, ca. 3 mi from Swansboro, W end of island, 11 Jul 1965, Wilbur 8459

(FSU, GA, GH). Pender Co.: Shell mound at Watts Landing, SE of NC 210 to Surf City,

Jun 1966, Bell 18575 (TENN). Rowan Co.: River banks near Salisbury, 1 Sep 1897,

Biltmore 1689c (US). South Carolina. Abbeville Co.: Floodplain levee of Johns Creek, compt. 176, stands 9-10, County Rd 159, 25 Oct 1992, Hill 24480 (USF). Anderson

Co.: Slopes overlooking stream in SW corner of county near Savannah River, 5 Sep

1949, Duncan 10229 (GA). Beaufort Co.: At docks, “River House” overlooking

Chechessee Creek, N end of Spring Island, 32.3437°N, 80.8387°W, 27 Mar 2004,

Nelson 24527 (USCH). Berkeley Co.: Old Santee Canal State Park, E of Moncks

Corner, S of Rt 17, 13 May 1988, Hill 19282 (USF). Calhoun Co.: Cave Hall, area behind spring water bottling plant, 33.5912°N, 80.5492°W, Pittman & Darr 08230008 /

796 (FSU). Clarendon Co.: Sand ridge NE of Santee River, ca. ¾ mi S of US 301, 16

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Sep 1967, Bozeman 11453 (AUA, FLAS, FSU, GA, MISS, UNA, USF). Dorchester

Co.: 1.25 mi SSW of Bacon Bridge over Ashley River, 18 mi NW of Charleston, 7 Apr

1944, Duncan 5895 (GA). Edgefield Co.: Just W of Horn Creek, Stand 7, Compartment

309, N side of Forest Service Rd 634, ca. 12 mi SW of Edgefield, 13 Oct 1997, Nelson

18864 (FSU). Fairfield Co.: Dutchmans Creek watershed, N side of Ridgeway, 17 Aug

1996, Grant 451 (USCH). Florence Co.: Shallow ravine opening onto Great Pee Dee

River, just above Bostick Landing off SC 66, 3 mi W of Bazen Crossroads, 33.9388°N,

79.4848°W, 23 Aug 2002, Pittman 08230205 & Darr 1564 (USCH). Georgetown Co.: E side of Little Bull Creek, N of Poacher’s Point, 305° 2.7 mi NW from northernmost point of Vaux Island, 33°35’23”N, 79°07’30”W, 15 May 1998, Nelson 19189 (FSU). Hampton

Co.: Bluff on N side of James Lake, near upper edge of Savannah River floodplain swamp, Webb Wildlife Center, ca. 6 air mi WSW of Garnett, 23 Jul 1999, Anderson

18907 (FSU). Horry Co.: Little River Inlet, 26 Jul 1919, Harris C19598 (US). Marion

Co.: Brittons Neck (Woodbury Tract), from confluence of Great Pee Dee and Little Pee

Dee Rivers to Hwy 378, 17 May 2006, Pittman et al. 05170607 (USCH). McCormick

Co.: Hillside near Rocky Creek, outskirt of granite rock area, 8.5 mi N 36° W of

McCormick, 22 Oct 1960, McComb 78 (GA). Orangeburg Co.: Along bluffs with limestone outcrop along Chapel Branch outside of Santee State Park, 12 Jul 2001,

Pittman 07120103 & Darr 961 (FSU, USCH). Tennessee. Bedford Co.: Roadside near

Normandy, 16 Jul 1948, Fairchild et al. 9967 (TENN). Blount Co.: Along High View Rd at Light Pink Rd, 7 May 1999, DeSelm s.n. (TENN). Bradley Co.: S of Cleveland, 30

Oct 1960, Cochran 27799 (TENN). Cannon Co.: Short Mtn, N side, N of Short Mtn Rd, ca. 2 mi W of Big Hill Rd, N down hollow toward Meltons Barn, 17 May 1987, Pyne 1762

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(TENN). Cheatham Co.: Vicinity of Sycamore Creek, Spring 1944, Shanks s.n. (TENN).

Davidson Co.: Without location data, 18 Jul 1934, Charlesworth s.n. (TENN). Decatur

Co.: Bill Martin’s old field barren near Bath Springs, 16 Jul 1985, DeSelm s.n. (TENN).

DeKalb Co.: Edgar Evins State Park, near ramp #2, 26 Jul 1995, DeSelm s.n. (TENN).

Dyer Co.: Dyersburg, 23 Apr 1920, Palmer 17263 (A). Franklin Co.: Roadside S of

Winchester, 4 Apr 1949, Sharp et al. 10804 (TENN). Giles Co.: Roadside, NE of

Pulaski, 13 Jul 1948, Sharp et al. 9795 (FSU). Grundy Co.: 5.7 mi W of and below

Monteagle, by I-24, 25 May 1974, Kral 52893 (TENN). Hamilton Co.: Chambliss

Preserve, W side of Lookout Mtn, 24 Oct 1953, McGilliard 18066 (TENN). Hardin Co.:

Slough near Tennessee River, S of Savannah, 7 Jul 1947, Sharp et al. 47-45 (TENN).

Hickman Co.: Laives Bend Community, 11 Nov 1969, Lynn s.n. (TENN). Jackson

Co.:Tator Knob, 1.8 mi SE of confluence of Spring Creek and Roaring River, Dodson

Branch Quad (1968), 36°19’20”N, 85°30’30”W, 4 May 1979, Patrick 2423 (TENN).

Knox Co.: Gallagher’s Ferry Rd, 11 Dec 1955, Galyon 20213 (TENN). Lake Co.: W edge of Reelfoot bottoms 2 mi NE of Phillippy, 10 Jul 1951, Shanks 15869 (TENN).

Lauderdale Co.: S of Ashport, 27 Jun 1948, Sharp et al. 8042 (TENN). Lewis Co.:

Parnassia site on Rt 99 at Langford Branch, 6 Jun 1981, DeSelm s.n. (TENN). Lincoln

Co.: Near Dellrose, 6 Apr 1949, Sharp 10850 (TENN). Loudon Co.: NNW facing bluff along Watts Bar Lake between river miles 593 and 594, just below Carmichael Island, 6

May 1984, Wofford 84-11 (TENN). Marion Co.: Ca. 1.2 mi S of Exit 158 of I-24, W side of Little Cedar Mtn, 35°00’55”N, 85°35’10”W, 25 May 2005, Estes 07595 (TENN).

Marshall Co.: Along Rt 99, ca. 0.8 mi W of Rt 31A, 4 May 1998, McNeilus 98-176

(TENN). Maury Co.: N side of Falls Creek, along trail parallel to creek, 22 Jul 2000.

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Estes 00910 (TENN). Monroe Co.: Along Rt 277, Green Road, 4 May 2000, DeSelm s.n. (TENN). Montgomery Co.: Near Palmyra, 14 May 1942, Shanks 1989 (TENN).

Moore Co.: SE of Lynchburg, 7 Aug 1947, Shanks et al. 5687 (TENN). Perry Co.:

Banks of Buffalo River at Campbell’s Fish Camp, ca. ¾ mi downstream from Sugar Hill bridge, 0.8 air mi due E of the bridge, 15 Sep 1967, Browne T-27 (TENN). Roane Co.:

Presbyterian Church Camp opposite Thiefsneck Island, Watts Bar Reservoir, 4 Jul

1960, Shanks 26942 (TENN). Robertson Co.: Bank of Red River, N of Cedar Hill, 27

Oct 1957, Sharp 22682 (TENN). Rutherford Co.: N of Luvergne by Lake Percy Priest,

3 Oct 1969, Kral 37499 (AUA, FSU, UNA). Sequatchie Co.: Terrace along Stone Creek at Stone Cave Rd, 30 Oct 1997, DeSelm s.n. (TENN). Shelby Co.: Shelby Forest park,

26 Apr 1949, Sharp et al. 10397 (TENN). Stewart Co.: Floodplain of Cumberland River, ca. 1 mi N of Dover, 13 Sep 1958, Brown s.n. (TENN). Trousdale Co.: Antioch, 23 Aug

1947, Shanks 7344 (TENN). Van Buren Co.: Fall Creek Falls State Park, near Wheeler

Farm, ca. 2.6 km W of jct Hwys 30 and 285, 17 Jul 2002, Fleming FCF-2168 (TENN).

Warren Co.: Rifle Range area, edge of Cumberland Plateau, 12 Apr 1949, Sharp et al.

11272 (TENN). Wayne Co.: E of Leatherwood, bluffs of Beech Creek, 22 Apr 1949,

Sharp et al. 10175 (TENN). White Co.: Below Grand Falls Dam, along Caney Fork near

Webb’s Camp, 31 July 1947, Sharp et al. 5032 (TENN). Williamson Co.: 4 mi N of

Franklin, 12 Jul 1979, Kral 63978 (GH, TENN). Wilson Co.: Cedar Glades, 2 mi N of

Lebanon, 29 Aug 1958, Godfrey 57500 (FSU). Texas. Hardin Co.: Savannah, ca. 4 mi

E of Sour Lake, 27 May 1957, Correll 16484 (GH). Jasper Co.: 15 mi SE from Zavalla on State Hwy 63 toward Jasper, turn R onto Farm Rd 255 for 4.3 mi, turn R for 7 mi to

Fed. Land Tract near Neches River, 6 Jun 1970, Nixon et al. 1851 (GH, LSU).

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Jefferson Co.: Beaumont, 16 Mar 1918, Palmer 13084 (A). Virginia. Accomack Co.:

S side of tributary of Taylor Branch, NW of St. Joseph’s Church, S of Middlesex, 26 Sep

1997, McAvoy 3073 (USCH). Charles City Co.: Above marsh on SW side of Herring

Creek on Westover Plantation, vicinity of Boy Scout’s Quonset hut, P.O. Barnetts, 27

May 1972, Ware 4222 (FLAS). Hampton, VA: Fortress Monroe, 30 May 1878,

Chickering s.n. (A). Isle of Wight Co.: Back of the beach of Burwell’s Bay, James

River, below Rushmere (Ferguson’s Wharf), 27 & 29 Aug 1940, Fernald & Long 12769

(GA, TENN). James City Co.: By James River, Grove Landing, SE of Grove, 19 Jul

1941, Fernald & Long 13419 (GH); SE side of mouth of Grove Creek at the James

River, 12 Jun 1982, Ware 7860 (FLAS). Norfolk Co.: Norfolk, 9 Jul 1904, Harrison s.n.

(GH). Prince George Co.: By James River, Upper Brandon, 16 Sep 1938, Fernald &

Long 9393 (GH, US). Princess Anne Co.: Little Neck, 6 Sep 1935, Fernald & Long

4988 (GH). York Co.: Carters Creek, York River, 20 Aug 1921, Grimes 4269 (GH).

Discussion. Sideroxylon lycioides, named by Linnaeus (1762), was the first

North American Sideroxylon to be described. Of the North American species, S. lycioides is the second most geographically widespread, found in much of the southeastern USA. Its distribution overlaps with that of the more widely distributed S. lanuginosum, both species ranging into areas of cold winters, and both absent from the southern half of Florida. Both are frequently inclined to arborescence. Sideroxylon lycioides is usually characterized by glabrous twigs and elliptic leaves with an acute to acuminate apex, although considerable variation exists in the species with respect to leaf size and shape, leaf apex, and fruit characters. This variation has prompted the recognition of varieties and segregate species. J.K. Small (1900) recognized two

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separate species, Bumelia lucida and B. cassinifolia. Clark (1942) noted that the name

Bumelia lucida was preoccupied by B. lucida Roem. & Schult., which apparently refers to a tropical species (Roemer & Schultes 1819), and he renamed B. lucida Small as B. smallii Clark. Bumelia smallii refers to a small-leaved variant with elliptic leaves and acute apices, whose distribution Clark (1942) stated to be mostly limited to areas west of the Mississippi River. Bumelia cassinifolia refers to a variant occurring from southwest Georgia to Louisiana, which Clark (1942, p. 175) describes as “… having the foliage characters of a very vigorous Bumelia reclinata and the fruiting characters of B. smallii.” Two varieties of Sideroxylon lycioides have been recognized based on leaf and fruit characters. Bumelia lycioides var. virginiana, recognized by Fernald (1936), is a variant having leaves with primarily a rounded apex, distributed from southeastern

Virginia westward to southern Indiana. Bumelia lycioides var. ellipsoidalis was recognized by Clark (1942) as a variant with ellipsoid fruit (as opposed to obovoid), distributed from Tennessee through northern Alabama and Mississippi to eastern

Arkansas. In agreement with Cronquist (1945), my examination of specimens leads me to conclude that leaf and fruit characters show continuous variation throughout the range of S. lycioides, therefore I do not recognize any infraspecific taxa.

Appearing fairly constant throughout the species are stomatal and hair characters. The structure of the stomatal complexes on the abaxial leaf surfaces of S. lycioides is unique (Fig. 5-2), each stomatal chamber consisting of a small, discrete dome, unornamented except for a single fine cuticular ridge neatly bordering it around the base, the chamber opening closed down to a narrow slit. The only other species having a similar configuration is S. thornei (Fig. 5-5). The remaining species in this

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group have stomatal chamber openings wide enough to allow the guard cells to be visible through them, and each opening is thickly surrounded by multiple rings of irregularly concentric cuticular ridges. These stomatal characters can only be usefully compared with the aid of a scanning electron microscope, but trichome characters can be seen with a dissecting microscope or even a good hand lens, making them useful for field identification. Trichomes on young leaves (and often on very young stems) of S. lycioides are transparent and colorless, and often flattened in cross-section, as distinguished from trichomes of the other species, which are typically pigmented or opaque and mostly terete in cross-section. Even older leaves of S. lycioides very often retain at least a scattering of these appressed, flattened, transparent trichomes.

Morphological phylogenetic analysis (Chapter 3) supports a close relationship between S. lycioides and S. thornei, indicating that the two species form a clade that is sister to the remaining species of section Frigoricola. Both species share a unique stomatal complex morphology that is different from that of the other species in the section, and both always have glabrous pedicels at anthesis. Chloroplast DNA analysis

(Chapter 3), in contrast to the morphological phylogeny, suggests a possible close relationship between S. lycioides and S. alachuense.

Nomenclatural notes. The name Bumelia pubescens Ten., appeared without description or comment in an appendix to a seed list (Tenore 1827), and it is thus a nomen nudum, It was later listed by Tenore (1829) as a synonym of B. ambigua.

Two syntypes exist for B. lucida Small–one from Louisiana, without data, J.L.

Riddell s.n. (NY #273371–Internet image!), and one without data, A. Featherman 95

(NY, not seen).

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Sideroxylon decumbens J.F. Gmel. (1792) is listed in Govaerts et al. (2001) in synonymy under S. lycioides. The name appears in the index of Syst. Nat. (Gmelin

1792), listed among the species on p. 397 of the book but the species is absent from p.

397; its inclusion in the index is an error.

2. Sideroxylon thornei (Cronq.) T.D. Pennington, Fl. Neotrop. Monogr. 52:170. 1990. Bumelia thornei Cronquist, Castanea 14:103. 1949. TYPE: U.S.A. GEORGIA. Early Co.: 1 mi E of Nantz Spring, 22 Oct 1947, Thorne 7345 (HOLOTYPE: GA 29170–Not seen).

Shrub, single to several-stemmed, 1–3 m tall, sometimes a small tree to 6 m tall, trunk diameter 2–8 cm, the bark even on older trunks relatively smooth, sometimes developing only shallow longitudinal and transverse fissures, plants not strongly stoloniferous. Indumentum of unicellular, light brown to blonde, rarely red-brown, T- shaped trichomes, symmetric or asymmetric, terete and hollow to flattened in cross- section, having a short stalk and a longer top portion of varying length, the top portions generally bent/curled and ascending. Vegetative buds densely pubescent with short, nearly sessile, appressed, straight to bent/curled, light brown to red-brown T-shaped trichomes, the stalk 0.01–0.03 mm long, the top 0.3–0.5 mm long. Young twigs (long shoots) 0.5–1 mm wide, terete, sparsely to moderately wooly-pubescent with ascending, blonde to light brown to red-brown T-shaped trichomes, the trichomes with stalk 0.07–0.15 mm long, top portion 0.6–1.4 mm long, top portions terete or flattened in cross section, straight or bent/curled, mostly ascending, twig becoming glabrate by end of first season, surface smooth, green to dark red-brown, prominently dotted with lenticels; thorns sometimes present at nodes, especially on younger stems, thorns 0.4–

1.8 (–3) cm long, occasionally lengthening to become side branches. Mature twigs glabrous, smooth, dark brown to grey-brown, dotted with lenticels, the bark of older

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branches remaining relatively smooth, woody galls sometimes present, leaves becoming clustered on stumpy brachyblasts, internode length 12–27 mm. Leaves tardily deciduous, alternate and spirally arranged on young long shoots, becoming fascicled on brachyblasts on older stems, petioles canaliculate, 4–15 (–19) mm long on young long shoots, 3–10 mm long on short shoots, and moderately to densely wooly-pubescent with ascending, blonde to light brown T-shaped trichomes, becoming glabrate with age; leaf blades highly variable in size and shape, blades on young long shoots 3.9–10.6 (–

13.9) cm long, 2.1–5.4 cm wide, ovate to elliptic to slightly obovate, sometimes rhombic or suborbicular, blades on short shoots 2.3–6.6 (–7.8) cm long, 0.7–3.5 cm wide, narrowly to broadly obovate to elliptic, sometimes rhombic or suborbicular, rarely ovate, coriaceous, the apex usually bluntly (infrequently sharply) acute, occasionally broadly rounded or retuse, the base acute to cuneate/decurrent, often slightly concave, the margin entire, blades of mature leaves flat; venation pinnate and visibly finely reticulate, brochidodromous, with secondary veins slightly decurrent, branching off midvein in opposite to alternate arrangement, ± in (6–) 8–12 irregularly spaced pairs, with an intersecondary vein occasionally occurring between secondaries, the tertiary veins irregular-reticulate, the quaternary veins irregular-reticulate to freely ramifying, areolation moderately developed, the marginal ultimate venation looped; adaxial surface dark green, glossy, with scattered fine, curled blonde trichomes when young, becoming glabrous, the midvein and secondary veins conspicuous, the tertiary vein reticulum evident but not boldly conspicuous, the veins impressed to flush (sometimes raised on dried specimens), the surface generally smooth; abaxial surface sparsely and evenly and persistently wooly-pubescent with light brown, ascending T-shaped trichomes, the

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trichomes mostly flattened (some terete) in cross-section, with stalk 0.08–0.2 mm long, upper portion 0.7–1.6 mm long, the upper portions bent and curled, ascending, pubescence more dense along midvein, the midvein and secondary veins raised and conspicuous; stomata (Fig. 5-5) recessed inside dome-like, ellipsoidal chambers raised slightly from the leaf surface, each chamber opening a narrow slit ca. 9–12 micrometers long, the guard cells not visible through the opening, each chamber dome neatly bordered by one or two narrow cuticular ridges forming a bead around the base of the dome, and extending radially from the base of each dome are bands of numerous, fine cuticular ridges parallel to each other, these bands of ridges ornamenting nearly all of the leaf surface in strong relief, with epidermal cell boundaries evident and marked by grooves or coarse ridges. Inflorescence a fascicle borne in a leaf axil, fascicles often clustered on short spur shoots in axils of fallen leaves, each cluster having 1–12 (–20) pedicellate flowers, the pedicels 6–12 (–17) mm long, glabrous. Calyx of 5 (–6) quincuncial, free sepals, the outer two sepals 1.8–2.9 mm long, 1.6–2.9 mm wide, suborbicular, the apex rounded, the margin entire, usually with a narrow membranous rim; the inner three sepals 1.8–2.5 mm long, 2–2.3 mm wide, ovate to suborbicular, the apex rounded, the margin entire to erose, with a broad membranous rim, outer sepals sparsely pubescent only near apex, the inner sepals sparsely pubescent over whole surface, or near apex only, all sepals having a fringe of short dark trichomes along apical margin. Corolla white, cyathiform, sympetalous, the tube 1.3–1.5 mm long, enclosed within the calyx; the lobes 5, exserted and spreading, glabrous, each with a median lobe and two lateral segments, the median lobe 2–2.2 mm long, 1.7–2 mm wide, orbicular, clawed, cupped around a stamen, the lateral segments 2.2–3 mm long

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(from junction with adjacent lateral segment), 1.8–2.3 mm long (from junction with median lobe), 0.6–1.2 mm wide, narrowly lanceolate, all corolla margins erose, translucent. Stamens 5, epipetalous, opposite the corolla lobes, exserted; filament 0.8–

2 mm long, 0.3–0.4 mm wide, fixed at top of corolla tube, dilated proximally and narrowing toward anther attachment; anther 1.1–1.4 mm long, sagittate, ventrifixed at the point of the sinus, extrorse, opening by two dorsal longitudinal slits. Staminodes petaloid, alternating with stamens, each staminode 1.7–2.2 mm long, 0.8–1.5 mm wide, reaching ca. 0.7–0.9 times the length of median corolla lobe, sometimes equaling or exceeding the median lobes, lanceolate to deltoid, infolded, base occasionally slightly reflex, margin erose, translucent. Ovary superior, 5–(6 –) loculate, locules uniovulate with basal-axile placentation, ovary ca. 1.1–1.2 mm long, 1–1.3 mm wide, subglobose, at anthesis densely strigose with pale to light brown T-shaped trichomes, the trichomes longer on distal part of ovary, pubescence sometimes denser over locules; style 1–1.3 mm long, glabrous, included, style tapering gradually to ovary, not appearing clearly separated with trichomes present on ovary, separation clearer with trichomes removed.

Fruit a berry, one (rarely 2)-seeded, 9–12 mm long, 8–11 mm wide, obovoid to subglobose, black, glossy, glabrous. Seeds 7.3–8.4 mm long, 6–7.5 mm wide, ellipsoid, the testa hard, smooth, glossy, the color solid light brown; the hilum scar basal, usually bipartite, the larger part basal, half-moon shaped to suborbicular, 1.5–2.2 (–2.7) mm long, 1.6–2.4 mm wide, the smaller part abaxial to the other part, shallowly U-shaped to straight, often very small, 0.8–2 mm long, 0.1–0.5 mm wide, the parts usually well- separated by a bridge of testa, the scar being the exposed portion of a hollow cavity

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under the testa extending a small distance around the basal end of the seed, the cavity filled, especially on the abaxial side, with a yellowish fatty substance. (See Fig. 5-6).

Phenology. Flowering May–June, fruit ripening September–November.

Common names. Swamp buckthorn; Georgia bully; Thorne’s buckthorn;

Thorne’s bumelia.

Distribution and habitat. The range of Sideroxylon thornei encompasses eighteen counties in southern Georgia, extending into six counties in the western

Florida panhandle, and three counties in southern Alabama (Fig. 5-7). It is found in the understory of forested wet sandy bottomlands over limestone, and woods bordering cypress ponds, in places where the soil is seasonally saturated but not completely inundated for long periods (Allison 1998, 2000).

Conservation status. Listed as Rare in Georgia, Endangered in Florida; ranked

S1–very rare in Alabama; global status G2–globally imperiled (Alabama plant atlas editorial committee 2014; Chafin 2008; Wunderlin & Hansen 2008).

Illustrations. Anderson (1996, Figures 2–16); Chafin (2008); Patrick et al. (1995, p. 25).

Specimens examined. USA. Alabama. Baldwin Co.: In the Mobile-Tensaw

River Basin, ca. 40 ft E of Smith Bayou at a point ca. 0.6 river mi E of its confluence with

Negro Lake, ca. 2.1 air mi NNW of Hurricane, NE ¼ OF SW ¼ of Sec. 18, T2S, R2E, 10

Aug 1997, Schotz 1533 (FSU). Geneva Co.: Ca. 8 mi S of Samson, bordering S side of

Pea River at jct with Hwy 87, E side of bridge, ca. 150–200 yds N of FL state line, 2 Mar

1997, MacDonald 10011, (FSU). Houston Co.: Ca. 9 mi S of Dothan, or 5 mi N of

Florida on US Hwy 231 at jct with Big Creek, 15 May 1994, MacDonald 7190 (UNA).

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Florida. Escambia Co.: Escambia River Water Mgmt Area, Mystic Springs Area, W bank of Escambia River, ca. 500 ft N of boat ramp, 21 Aug 2004, Burkhalter 20009

(FSU). Franklin Co.: L bank of Apalachicola River just below Ft. Gadsden State Park, ca. river mi 19.3, T6S, R8W, NE ¼ of SW ¼, Sec. 3, 17 Nov 1995, Anderson 16114

(FSU). Gulf Co.: On Forbes Island near L bank of Apalachicola River, S of powerline crossing, T6S, R8W, SE ¼, Sec. 23, 17 Nov 1995, Anderson 16111 (FSU); W bank of

Apalachicola River at ca. river mi 23.0, halfway between mouths of Owl Creek and

Brushy Creek, T6S, R8W, NE ¼ of SW ¼, Sec. 3, 2 Nov 1995, Light & Darst s.n. (FSU).

Holmes Co.: Ca. 5 mi W of Graceville, S side of Hwy 2 at jct with Wrights Creek, 14

Jun 1997, MacDonald 10703 (UNA). Jackson Co.: W side of FL 271, 16.2 mi N of

Sneads, 20 Oct 1987, Godfrey 82601 (GA); W side of FL 271, 16.2 mi N of US Rte 90 at Sneads, 13 Jun 1988, Godfrey 82691 (FSU); W side of FL 271, 16.2 mi N of Sneads,

18 Oct 1990, Godfrey 84015 (A). Santa Rosa Co.: E end of Grimes Lake, Eglin Air

Force Base, ca. 1.15 mi E of Parkersville, S side of Yellow River, NE ¼ of SE ¼, Sec. 2,

T1N, R26W, 1 Aug 1994, Schotz 1142 (FSU). Georgia. Baker Co.: Ca. 9.2 air mi NW of Newton, ca. 2.9 air mi NNE of Elmodel, N of Clear Lake Rd (Co. Rd 121), W side of

Chickasawhatchee Creek, 15 May 1997, Allison 9817 (GA, USCH). Calhoun Co.: 5 mi

SSE of Morgan, 3.5 mi WSW of Leary, N of GA Hwy 62, above E bank of

Ichawaynochaway Creek, 23 May 1990, Allison 4458 (GA). Crisp Co.: Ca. 9.6 air mi

SW of Cordele, N bank of Swift Creek, just E of Primrose Bridge Rd (Co. Rd 105, including the RR bridge, the 3rd bridge E of GA Hwy 200 bridge, 14 May 1997, Allison

9807 (FLAS, FSU). Decatur Co.: Ca. 10.4 mi WNW of Bainbridge and S of Brinson, ca.

1.7 air mi due S of US 84/GA 38 bridge over Spring Creek, 24 Oct 1990, Allison 5058

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(GA). Dougherty Co.: Ca. 13.4 air mi WSW of Albany, off both sides of GA Hwy 62, ca.

4.4 rd mi W of Coolewahee Creek, E of E fork of Kiokee Creek, edge of floodplain, 7

Aug 1996, Allison 9893 (GA). Early Co.: Ca. 15.7 mi ENE of Blakely, ca. 3.25 mi ESE of Arlington, just N of Co. Rd 160 (type locality), 22 May 1990, Allison 4446 (GA); 1 mi E of Nantz Spring, SE of Arlington (type locality), 14 Aug 1986, Godfrey 82063 (FSU).

Laurens Co.: Ca. 7 air mi SE of Dublin, River Bend Wildlife Mgmt Area, N side of rd to

Troup Lake, 6 May 1997, Allison 9740 (FLAS, GA). Lee Co.: Ca. 11.4 air mi NNW of

Leesburg, 3.4 mi ESE of Smithville, floodplain of Muckalee Creek, a little N of GA Hwy

188 and E of creek, 6 Nov 1996, Allison 9644 (FLAS, GA). Liberty Co.: Fort Stewart

Military Reservation, Training area E2, SE side of rd to Ammunition Supply Point, ca.

0.75 mi NE of GA 144, labeled Cedar Bay on base map and topo quad, 19 Aug 1993,

Moore 1856 (GA). Miller Co.: Ca. 0.6 mi SW of Colquitt, Colquitt Swamp along Spring

Creek, W of creek and S of US Hwy 27, 30 Aug 1990, Allison 4715 (GA). Pulaski Co.:

NNW of Hawkinsville, Ocmulgee Wildlife Mgmt Area, floodplain of Ocmulgee River, ca.

2 mi WSW of Lizzie Bloomer Church, 6 Oct 1999, Allison 12257 (FLAS, GA). Seminole

Co.: Ca. 5.8 air mi E of Donalsonville, ca. 2.8 mi NE of Iron City, W side of Dry Creek, N of Lane Bridge Rd (Co. Rd 16), 15 May 1997, Allison 9822 (FLAS, FSU). Sumter Co.:

Ca. 9.3 air mi SSE of Americus, ca. 3.1 air mi ESE of Sumter, floodplain of Muckalee

Creek, N of the E-most bridge on Three Bridges Rd, 6 Nov 1996, Allison 9641 (FSU,

GA). Tattnall Co.: Ca. 17.7 mi SSE of Reidsville, ca. 9.8 mi SW of Glennville,

31°50’06”N, 82°02’40”W, 25 Sep 1997, Allison 10112 (FLAS). Telfair Co.: Ca. 18.7 mi

SSE of McRae, ca. 7 mi ESE of Jacksonville, Horse Creek Wildlife Mgmt Area, lower end of Coffee Branch Slough, 11 Nov 1997, Bozeman s.n. (FSU, GA). Terrell, Co.: Ca.

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8.1 air mi SSE of Dawson, ca. 3 air mi SSE of Herod, just E of Co. Rd 130 at a point ca.

0.2 mi N of bridge over Chickasawhatchee Creek, 9 Aug 1996, Allison 9396 (GA, FSU).

Wilcox Co.: Ca. 16.4 air mi ESE of Rochelle, Bowens Mill Fish Hatchery, N edge of floodplain of House Creek, 25 Oct 1996, Allison 9622 (FLAS, FSU, GA). Worth Co.: Ca

16.75 air mi NW of Sylvester, ca. 3.3 mi ESE of Oakfield, along and near N side of

James Creek, W of Co. Rd 118, 14 May 1997, Allison 9805 (FLAS, FSU, GA, USCH).

Discussion. Sideroxylon thornei was first collected in 1940 (Anderson 1996;

Patrick et al. 1995). It was described by Cronquist (1949) based on collections from southwestern Georgia by R.F. Thorne, for whom he named the species. Although S. thornei is a wetland plant, Cronquist, in his protologue (1949), erroneously gave the habitat of the type locality as dry woods, creating subsequent confusion in the concept of the species, even though Thorne (1949, 1954) had indicated that the habitat is moist.

A published treatment of Georgia’s protected plants (McCollum & Ettman 1977) perpetuated this misconception of S. thornei as a low shrub of dry habitats. Until this was corrected by Godfrey (1988) and in a revised treatment of protected Georgia plants

(McCollum & Ettman 1991), collections of low-growing dry sandhill plants that would later be described as S. macrocarpum (Nutt.) J.R. Allison were considered conspecific with S. thornei (Allison 2006). Cronquist (1949) noted that S. thornei appeared to combine features of S. reclinatum (small leaves; low habit, to 1.5 m tall) and S. lanuginosum (wooly leaf pubescence; large fruit), and speculated that S. thornei might be of hybrid origin, a view that was repeated by Pennington (1990). But subsequent observations indicate that S. thornei often grows to a height of 6 m, often has larger leaves than S. reclinatum, and Anderson (1996) presented evidence from scanning

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electron microscopy revealing that the stomatal and epicuticular micromorphology of the lower leaf surface of S. thornei is quite unique and different from that of either S. lanuginosum or S. reclinatum, all of which weaken the argument for hybrid origin.

Stomatal complex morphology of S. thornei is actually rather similar to that of S. lycioides (Figs. 5-2, 5-5), suggesting a close relationship between these two species that is supported by morphological phylogenetic analysis (Chapter 3). Now considered more abundant than originally thought, Sideroxylon thornei is nevertheless a relatively narrowly endemic species whose wetland habitat is threatened by conversion to pine plantations and agriculture and by excessive withdrawal of water from the aquifer

(Patrick et al. 1995; Allison 1998; Chafin 2008).

3. Sideroxylon tenax L., Mant. Pl. 1:48. 1767. Bumelia tenax (L.) Willd., Sp. Pl. 1:1085. 1798. Sideroxylon chrysophylloides Michx., Fl. Bor.-Amer. 1: 123. 1803, nom. superfl. Bumelia chrysophylloides Pursh, Fl. Amer. Sept. 155. 1814. Sclerocladus tenax (L.) Raf., Sylv. Tellur. 35. 1838. Sclerozus tenax (L.) Raf., Autik. Bot. 73. 1840. Lyciodes tenax (L.) Kuntze, Revis. Gen. Pl. 2: 406. 1891. TYPE: U.S.A. SOUTH CAROLINA: without specific locality, A. Garden s.n. (HOLOTYPE: LINN 261.5–internet image!).

Chrysophyllum carolinense Jacq. Observ. Bot. 3:3, Pl. 54. 1768. Sideroxylon carolinense (Jacq.) Sarg., Rep. For. N. America: 101. 1884. TYPE: U.S.A. SOUTH CAROLINA: Without locality data, M. Catesby s.n. (LECTOTYPE, here designated: OXF, Sher-0512-10–internet image!)

Sideroxylon sericeum Walt. Fl. Car. 100. 1768. TYPE: U.S.A. SOUTH CAROLINA. CHARLESTON CO.: Francis Marion National Forest, Sewee Trail to Shell Ring, near Atlantic Intracoastal Waterway at edge of saltmarsh, 3 Oct 2000, A.B. Pittman & A.R. Darr 717 (NEOTYPE, here selected: USCH!; ISONEOTYPE: FSU!)

Bumelia megacocca Small, Bull. New York Bot. Gard. 1: 441. 1900. TYPE: U.S.A. FLORIDA. HILLSBOROUGH CO.: Tampa, Oct 1877, A.P. Garber s.n. (HOLOTYPE, NY–internet image!).

Bumelia lacuum Small, Man. S.E. Fl. 1034, 1507. 1933. TYPE: U.S.A. FLORIDA. HIGHLANDS CO.: Ancient sand dunes north of Kuhlman, 25 Apr 1921, J.K. Small & J.B. DeWinkeler 9965 (LECTOTYPE, here designated: NY–internet image!; ISOLECTOTYPES: FLAS!, GH!, TENN!)

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Shrub, single to many-stemmed, or small tree to 10 m tall, trunk diameter 1–17 (–

36) cm, the bark of older trunks thick, grey-brown, and divided by deep, red-tinged fissures, young plants sometimes stoloniferous. Indumentum of unicellular, silver-white to golden to dark red-brown T-shaped trichomes, symmetric or asymmetric, the trichomes terete and hollow or flattened in cross-section, having a short stalk, and a longer top portion of varying length, the top portion straight to curved to curled.

Vegetative buds densely wooly-pubescent with short, dark red-brown to light golden T- shaped trichomes, the trichomes terete to flattened-twisted in cross-section, with stalk

0.02–0.05 mm long, top portion 0.15–0.35 mm long, the top portions appressed to curved-ascending to curled. Young twigs (long shoots) terete, 1.5–2 mm wide, densely and finely pubescent (usually through the first season) with dark red-brown to light golden T-shaped trichomes, most of the trichomes flattened-twisted in cross-section

(some terete), the stalk 0.02–0.07 mm, the top 0.2–0.9 mm, many of the top portions straight and appressed and oriented ± lengthwise along the twig, while many are curved-ascending or curly, giving a sericeous-tomentulose texture, the twig surface dark red-brown, becoming dark gray-brown, prominently dotted with lenticels and developing short, fine longitudinal fissures that lengthen with age of twig; thorns often present at nodes, especially on younger stems, thorns 0.6–1 (–2) cm long, some becoming short spur shoots or lengthening to become side branches. Mature twigs sparsely pubescent becoming glabrous, the surface dark brown to gray-brown, prominently dotted with lenticels, with longitudinal fissures and often also short transverse fissures appearing with age, the leaves clustered on stumpy brachyblasts (short spur shoots), internode length 5–25 (–45) mm. Leaves tardily deciduous, alternate and spirally arranged on

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young long shoots, becoming fascicled on brachyblasts on older stems, petioles canaliculate, 2–13 mm long on young long shoots, 1.5–11 mm long on short shoots, and persistently pubescent with a moderate to dense shaggy-strigose indumentum of blonde to dark red-brown T-shaped trichomes, the hair tops appressed to ascending and oriented lengthwise along the petiole; leaf blades on young long shoots 14–85 mm long, 6–38 mm wide, blades on short shoots 10–70 mm long and 4–30 mm wide, oblanceolate to broadly obovate, sometimes elliptic, coriaceous to sclerophyllous, flat to slightly V-infolded along midvein, the apex rounded, occasionally retuse or emarginate, to bluntly (infrequently sharply) acute, the base narrowly to broadly cuneate, occasionally decurrent, the margin entire and slightly revolute; venation conspicuously finely reticulate, the primary venation pinnate, brochidodromous, with secondary veins slightly decurrent, branching off midvein in opposite to alternate arrangement, ± in 3–14 irregularly spaced pairs, with an intersecondary vein occasionally occurring between secondaries, its length ca. 50% the length of the secondaries, its distal course reticulating, the tertiary and quaternary veins irregular-reticulate, the quinternary veins irregular-reticulate to freely ramifying, areolation moderately developed, the marginal ultimate venation looped; adaxial surface green, glossy, pubescent when very young with moderate to dense but quickly deciduous sericeous-wooly indumentum, becoming glabrate, the vein reticulum evident, midvein and secondaries prominent, the midvein impressed, higher-order veins slightly impressed to flush with surface (fresh leaf) to conspicuously raised (dried leaf); abaxial surface covered with dense, persistent indumentum of light golden to dark red-brown T-shaped trichomes, the trichomes terete to flattened-twisted in cross-section, their smooth surfaces sometimes dulled by copious

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deposits of epicuticular wax, with stalk 0.02–0.075 mm long, top portion 0.36–1 mm long, the top portions mostly straight, appressed, multi-layered, and co-oriented ± parallel to the secondary veins, the indumentum appearing lustrous and silky, or sometimes dull and finely wooly due to a larger proportion of trichomes being curled and ascending, the indumentum completely obscuring the leaf surface, with only the midvein, secondary veins, and some tertiary veins raised and thereby evident; stomata

(Fig. 5-8) recessed inside dome-like chambers raised from the leaf surface, the chamber openings thick-rimmed, round to broadly elliptic, each opening centered in the cup-shaped surface of a raised, broad donut-shaped complex of irregularly concentric cuticular ridges that form a shallow bowl with the opening in the center, the guard cells clearly visible through the opening, the surface between stomata smooth and irregularly undulating, epidermal cell boundaries sometimes evident, faintly marked by smooth ridges or shallow grooves. Inflorescence a fascicle borne in a leaf axil, several fascicles often tightly clustered on short spur shoots in axils of fallen leaves, each fascicle having ca. 4–20 pedicellate flowers, the pedicels 2–12 (–15) mm long, persistently pubescent at anthesis with dense, shaggy-strigose indumentum of blonde to golden to dark red- brown T-shaped trichomes, the hair tops appressed to ascending, the pedicels sometimes becoming glabrate in fruit. Calyx of 5 (–6) quincuncial, free sepals, the outer two sepals 2–2.5 mm long, 1.5–2 mm wide, elliptic to suborbicular, the apex rounded, the margin entire with very narrow membranous rim; the inner three sepals 2.3–2.7 mm long, 2–2.5 mm wide, elliptic to suborbicular, the apex rounded, the margin entire to erose, with broad membranous rim on one side or both; all sepals persistently pubescent with dense, shaggy-strigose indumentum of blonde to golden to dark red-

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brown T-shaped trichomes, the hair tops appressed to ascending. Corolla white, cyathiform, sympetalous, the tube 1.5–2 mm long, enclosed within the calyx, the lobes 5

(–6), exserted and spreading, glabrous, each with a median lobe and two lateral segments, the median lobe 1.4–2.2 mm long, 1.2–1.8 mm wide, suborbicular, clawed, cupped around a stamen, the lateral segments 2–2.5 mm long (from junction with adjacent lateral segment), 1–1.7 mm long (from junction with median lobe), 0.5–0.9 mm wide, lanceolate, margins erose, translucent. Stamens 5 (–6), epipetalous, opposite the corolla lobes, exserted; filament 1.5–2.5 mm long, 0.2–0.3 mm wide, fixed at top of corolla tube, dilated proximally and narrowing toward anther attachment; anther 1.1–1.5 mm long, 0.5–0.7 mm wide, sagittate, ventrifixed near the point of the sinus, extrorse, opening by two longitudinal slits. Staminodes petaloid, alternating with stamens, each staminode 1.7–2.6 mm long, equaling or sometimes exceeding the median corolla lobes, 1.1–1.8 mm wide, ovate, infolded, base sometimes reflexed, margin erose, translucent. Ovary superior, 5– (6–) loculate, locules uniovulate with basal-axile placentation, ovary ca. 0.9–1.4 mm long, 0.9–1.2 mm wide, subglobose, tapering abruptly to style, the ovary at anthesis densely pubescent with a sericeous indumentum of golden to dark red-brown T-shaped trichomes, the hair tops straight, appressed, and longer on distal part of ovary; style 1.1–1.5 mm long, glabrous, included. Fruit a single- seeded berry (rarely 2-seeded), 7.3–14.5 mm long, 7–13.8 mm wide, subglobose, black, glossy, glabrous. Seeds 7–13 mm long, 5.4–8.6 mm wide, ellipsoid, the testa hard, smooth, glossy, the color variegated light brown mottled with cream-color, or sometimes nearly solid brown; the hilum scar basal, usually bipartite, one part containing the funiculus and usually larger, of variable size and shape, from irregular to

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suborbicular to half-moon shaped, 0.8–3.2 mm long, 0.7–4 mm wide, and a smaller, laterally elongate part abaxial to the other part, generally curved or V-shaped, 1.4–3.4 mm long, 0.4 –1 mm wide, the two parts separated by a bridge of testa or occasionally running together, the scar being the exposed portion of a hollow cavity under the testa extending a small distance around the basal end of the seed, the cavity filled, especially on the abaxial side, with a yellowish fatty substance. (See Figs. 5-9, 5-10, 5-11).

Distribution and habitat. A plant of xeric, deep-sand soils, Sideroxylon tenax is found on and around sandy dune habitats of the modern coastline of Florida, Georgia, and South Carolina, ranging sparingly into extreme southern coastal North Carolina.

The species also grows quite abundantly in upland scrub habitats throughout the ancient dunes of Florida's central peninsular sand ridges, from the Trail Ridge southwest of Jacksonville southward to the Lake Wales Ridge in Polk and Highlands

Counties. It is less abundant but still present in some of Florida's peninsular Gulf coast counties. (Fig. 5-12). Its association with current and former coastal sand dunes indicates that S. tenax originated as a coastal species, endemic to Florida and a stretch of southeastern North American coastline.

Phenology. Flowering May–July, fruit ripening September–October.

Common names. Tough bumelia, tough bully.

Illustrations. Godfrey (1988, Fig. 322, by Melanie Darst); Jacquin (1768, Pl. 54);

Sargent (1893, Tab. 246).

Specimens Examined. USA. Florida. Brevard Co.: Sebastian Inlet State Park, landward side of beach dunes, N of inlet, 27°51’50.0”N, 080°26’57.7”W, 3 Oct 2012,

Corogin 1193 (FLAS); Malabar Cape, S of Melbourne Beach, between US A1A and

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Indian River, 22 May 1965, Lakela 28655 (GA). Citrus Co.: Along FL 491, just W of jct with FL 200, near N end of Lake Tsala Apopka, 16 Oct 1964, Beckner 639 (FLAS). Clay

Co.: Hammock on river, Green Cove Spring, 31 Aug 1937, Arnold s.n. (FLAS); FL Rt

315, at Clay-Putnam Co. line, 26 Mar 1992, Platt 239 (LSU). Collier Co.: Horr's Island, on shell ridge, 3 Sep 1970, Avery 2042 (FLAS). Duval Co.: Near Jacksonville, 27 Aug

1896, Curtiss 5678 (USF). Flagler Co.: Washington Oaks State Park, W side, 6 Jul

1972, Long et al. s.n. (USF). Hernando Co.: Withlacoochee State Forest, McKethan

Park, 2 Sep 1978, Lassiter 172 (USF). Highlands Co.: Archbold Biological Station,

27°08’39”N, 081°21’23.4”W, 17 Sep 2012, Corogin 1175 (FLAS); slope of Lake Wales

Ridge, Archbold Biological Station, Sep 4 1981, Correll 52431 (USF); ca. 1 mi SW of

Kuhlman, just S of Lake Josephine along Lake Josephine Rd, T35S, R29E, Sec. 33, NE of SE, 21 Jun 1979, Hansen & Richardson 5799 (USF); Sebring, along FL Rt 17 just N of jct with US 27, 23 Jul 1983, Judd 3383 (FLAS); along Rt 27 S of Sebring, ca. 1 mi N of jct with Rt 66, 23 Jul 1983, Judd 3383 (FLAS); vicinity of Josephine Creek and US 27

S of Kuhlman, 25 Jun 1962, Ray & Lakela 11054 (GH,USF);.sand-hills between Avon

Park and Sebring, 30–31 Aug 1922, J.K. Small et al. 10666 (syntype of Bumelia lacuum

Small, NY–internet image!). Hillsborough Co.: Balm-Boyette Tract, 2.5 mi S of

Boyette, T1S, R21E, Sec 17, NE quarter, 5 May 1995, Vandaveer s.n. (USF). Indian

River Co.: W side of US 1, about 5.6 mi S of Vero City, 11 May 1963, Lakela 25972

(USF). Lake Co.: Along FL 561, 2.1 mi S of Astatula, 16 May 1976, Baltzell 8437

(FLAS); Palatlakaha River Park, along nature trail through scrub area, 28°30’12”N,

081°45’7.4”W, 3 Sep 2012, Corogin 1168 (FLAS); E side of Grassy Lake, 1.5 mi NE of

Minneola, S5, T22S, R26E, 27 May 1972, Ward 8338 (GA). Levy Co.: Cedar Keys, Apr

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1876, Garber s.n. (FLAS). Manatee Co.: South Fork State Park, T33S, R21E, Sec. 7,

16 May 1992, Owens SF0094 (USF). Marion Co.: Silver River State Park, N of Rt 314

(Sharpes Ferry Rd), E of Rt 35, T15S, R23E, Sec 7, 12 Jun 1996, Anderson 16590

(FSU); Ocala National Forest, Mormon Branch area E of SR 19, 29°11’59.6”N,

081°39’15.3”W, 8 Nov 2012, Corogin 1250 (FLAS); Tobacco Patch Landing, Ocala

National Forest, 15 Jul 1949, Mather & Arnold M-385 (GA). Martin Co.: Rocky Point

Hammock Park, Salerno, SE Kubin Ave & SE Harbor Ter., ca. 2.25 mi E of US 1, ca.

1.1 mi N of Cove Rd, 27°09.470'N, 80°11.080'W, 8 Jun 1998, Bradley & Woodmansee

1011 (USF). Nassau Co.: Ralph E. Simons State Forest, 3–4 air mi SE of Folkston, GA,

25 Jun 1999, Anderson 18974 (FSU). Orange Co.: Big Sand Lake SE (Oran26), Sec.

12, T24S, R28E (Lake Jessamine quad), 16 Dec 1987, Christman 2201 (FLAS).

Osceola Co.: Ca. 1.5 mi N of Polk Co. line, T25S, R27E, SW quarter, 6 Oct 1992, Grey s.n. (USF). Palm Beach Co.: Yamato Scrub in Boca Raton, 12 May 1999, Austin CS-2

11/70 (FSU). Pasco Co.: Just W of Blanton on FL 41, ca. 2 mi E of US 75, 21 Jul 1974,

Wunderlin et al. 5316 (USF). Polk Co.: Blue Lake Scrub (Polk 03), Sec 14, T28S, R25E

(Auburndale quad), 3 Mar 1987, Christman 1425 (FLAS); Tiger Creek Preserve, Sec. 1-

36, Ridge C., 7 Oct 1987, Christman 1967 (FLAS); Saddle Blanket Scrub Preserve, area E of entrance, near Avon Park Cutoff Rd, 27°40’19.7”N, 081°34’25.3”W, 2 Sep

2012, Corogin 1164 (FLAS); Tiger Creek Preserve, N of office bldg., 27°48’38.1”N,

081°28’59.6”W, 16 Sep 2012, Corogin 1173 (FLAS); 6 mi E of Haines City, along FL

580 at "Palm Gardens," 18 May 1965, Conard s.n. (FLAS); 8 mi N of Avon Park, by US

27, 1 Jun 1980, Godfrey 77885 (FSU); Frostproof, off Rt 630A, 2 Jun 1961, Lakela

24218 (USF); 2.5 mi W of Frostproof, 7 Jun 1967, McDaniel 9206 (FSU). Putnam Co.:

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Beecher's Spring, just S of Conservation Reserve, 1 May 1965, Wiggins 19934 (FLAS).

St. Johns Co.: St. Augustine, in cemetery near corner of Old Moultrie Rd and King’s

Estate Hwy, SW part of cemetery where occupied plots end, 19 Aug 2012, Corogin

1141 (FLAS); Anastasia State Park, on dunes landward of beach, 29°52’01.6”N,

081°16’23.9”W, 26 Aug 2012, Corogin 1142 (FLAS); Castillo de San Marcos National

Monument, St. Augustine, FL A1A across from Old City Gates, W shore of Matanzas

Bay, 31 May 2003, Giannasi & Zomlefer 232 (GA). St. Lucie Co.: Within town limits of

Indrio, by US 1, 8 June 1984, Godfrey 81354 (FSU); W of Intracoastal Waterway, close to northern boundary, off US 1, N of St. Lucie, 28 Jul 1962, Lakela 25222 (USF); just S of Indian River Co. line along US 1, 27 June 1962, Ray & Lakela 11092A (USF).

Volusia Co.: Roadside NNW of Ormond, between Tomoka River and Halifax River, 20

Oct 1999, Allison 12304 (FLAS); 9 mi SE of Sanford, by FL Rt 46, 8 Jun 1984, Godfrey

81355 (FSU); Turtle Mound, 24 May 1926, J.K. Small et al. 12929 (GA). Georgia.

Brantley Co.: Top of sandy bluff along Satilla River, S of Atkinson, 22 May 1969,

Duncan 23260 (GA). Bryan Co.: Ca. 11 mi SE of Richmond Hill, ca. 1.3 mi NNE of

Kilkenny, Richmond Hill Wildlife Mgmt Area, 22 Jul 1999, Allison 12114 (FSU). Camden

Co.: N of St. Marys, Crooked River State Park, near shell midden area, 24 Jun 1999,

Allison 12053 (FLAS); Cumberland Island National Seashore, Rollercoaster Trail ("High

Point"), near Lake Whitney, NE coast of Cumberland Island, 30°54'N, 81°24.88'W, 17

Jun 2004, Giannisi & Zomlefer 992 (GA). Charlton Co.: Bluff overlooking St. Marys

River at Trader's Hill, E of Rt 23, few mi SW of Folkston, 9 Jul 1999, Anderson 18862

(FSU). Chatham Co.: Tybee Island, N side of US 80, just E of bridge over Lazaretto

Creek, 32°00’55.7”N, 080°52’40.7”W, 31 Oct 2012, Corogin 1248 (FLAS); S of

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Savannah, Ossabaw Island State Wildlife Mgmt Area, NE edge of island along both sides of unnamed extension of Bradley Rd, well NE of Main (Beach) Rd, 27 Jul 1999,

Allison 12135 (FLAS); S of Savannah, Ossabaw Island State Wildlife Mgmt Area, central eastern edge of island, E of Bradley Rd, NE of jct Main (Beach) Rd, 27 Jul 1999,

Allison 12134 (FLAS). Glynn Co.: SE of Brunswick, Jekyll Island State Resort Park, S end of island, S of intersection of Macy Lane and St. Andrews Rd, 3 Sep 1999, Allison

12195 (GA). Liberty Co.: Sunbury, Ft. Morris State Historic Site, along Medway River,

22 Jul 1999, Allison 12116 (FSU); St. Catherines Island, N end, N of Seaside Creek, 13

Jun 1984, Jones 24217 (GA). McIntosh Co.: NNE of Darien, Harris Neck National

Wildlife Refuge, ca. 2.4 mi by road from W entrance to the NWR, abandoned airfield, 2

Sep 1999, Allison 12188 (USCH); dunes near S end of Sapelo Island, 20 Jun 1956,

Duncan 20172 (USF). North Carolina: New Hanover Co.: Near Wrightsville Beach, 18

Apr 1919, Harbison 191 (A). South Carolina. Beaufort Co.: Across channel and E of the N end of St. Phillip Island, 24 Aug 1979, Leonard s.n. (FSU); Buzzard Island,

32.2478°N, 80.7806°W, 21 Apr 2000, Pittman 04210009 (US). Charleston Co.: Edisto

Beach, maritime forest, 26 Oct 1957, Ahles 38123 (USF). Colleton Co.: Spanish Shell

Mound at terminus of nature trail in Edisto State Park, 22 Jul 1999, Anderson 18888

(FSU). Hampton Co.: Hamilton Ridge, floodplain of Savannah River, 1 Jun 2000,

Pittman 06010010 (US, USCH). Jasper Co.: Along E side of Forks Lake (Mayers

Lake), on the Savannah River, ca. 5 miles NW of Hardeeville, Aulbach-Smith 2750

(OKL); Tillman Sand Ridge Heritage Preserve, ca. 6 mi W of Tillman, nature trail just W of parking area on W side of Hwy 119, 23 Jul 1999, Nelson & Anderson 20648 (USCH);

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Discussion. Sideroxylon tenax is a plant of beach dunes. Named by Linnaeus

(1767), S. tenax was the second North American species of Sideroxylon to be described

(the first was S. lycioides). Tolerant of drought and salt, living up to its specific epithet, it grows in sandy dune habitats–modern dunes of the Atlantic coastline, as well as ancient dunes of Florida’s interior sand ridges. These ridges represent former coastlines during times of higher sea level during the past several million years. The plant can be a bushy or scraggly shrub, or a small single-trunked tree, older trees often with a single large- diameter base to half a meter tall, branching into two to several main trunks that can ascend to a height of 10–12 meters with a spreading crown. The largest tree observed during this study (Corogin 1141) had a single straight trunk, 36 cm in diameter, a height of ca. 10 m with a spreading crown, growing in a cemetery in St. Augustine, FL.

The plants of the central Florida peninsula, especially on the southern ridges, are often morphologically distinct from those of the modern coastlines. The trend on the inland ridges is toward darker-colored and less lustrous abaxial leaf pubescence, smaller leaves, shorter pedicels, and perhaps a greater tendency to form stoloniferous clones. On plants of the interior ridges, the abaxial leaf pubescence is typically tawny to very dark brown, and appears dull and finely wooly, rarely silky-sericeous, while leaf indumentum of coastal plants is tawny to light golden to even silvery-white, most often appearing silky and lustrous, although it is sometimes dull and wooly (See Figs. 5-9, 5-

10, 5-13). In the wooly form, most trichomes are straight, appressed, multi-layered, and co-oriented as in the silky form, completely obscuring the leaf surface, but there is a large proportion of trichomes that are curled and ascending, dulling the luster. While silky and wooly forms occur intermixed in coastal and some inland areas, plants of the

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central ridges, especially the southern portion (Polk and Highlands Counties) are predominantly of the dark colored and wooly form. Leaf size is a highly variable character in all southeastern USA Sideroxylon taxa, but leaf size trends smaller in plants of the southern ridges (Polk and Highlands Counties), where the largest leaves on short shoots rarely exceed 4.5 cm in length, while in Atlantic coastal plants, largest short-shoot leaves can be up to 8 cm long. There is a very consistent difference in mean pedicel length between Atlantic coastal populations (Florida through South

Carolina) and those of Florida's interior ridges. Mean pedicel length of coastal plants is longer (9.3 mm; range 4–15 mm) than that of interior ridge plants (4.8 mm; range 2–11 mm). In habit, S. tenax ranges from scraggly many-stemmed shrub to spreading single- trunked tree. In the pyrogenic scrubs of Florida's interior sand ridges, the plant is shrubby, often dwarfed, and sometimes stoloniferous, with aerial shoots sprouting from horizontal runners. This clonality appears more common in interior scrubs than in coastal dunes, and, along with dwarf habit, short pedicels, and wooly leaf pubescence, this character was used to distinguish the interior scrub variant from S. tenax as a separate species, i.e., Bumelia lacuum Small (Small 1900; Clark 1942; Lakela 1963).

However, clonality and dwarfness are not absent from coastal dune populations, and S. tenax also occurs as a single-trunked tree in interior scrubs, particularly in overgrown scrubs that have not seen fire in many decades. In leaf pubescence, although the wooly form predominates in populations on the interior ridges, wooly and silky forms and their intermediates are found in all populations. In leaf size, and especially pedicel length, regional trends are unmistakable as one goes from the Atlantic coast to Florida's interior sand ridges, but the differences are not sharply enough demarcated to warrant separate

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taxonomic status for the interior scrub variant of S. tenax. Therefore, Bumelia lacuum is considered within the synonymy of S. tenax.

Sideroxylon tenax, including its interior scrub variant, along with S. alachuense, form the Sideroxylon tenax complex (Fig. 5-13), as they share in common two distinctive characters. First, both have an abaxial leaf indumentum with trichomes appressed, co-oriented, and multi-layered, completely obscuring the leaf surface.

Second, both have stomatal complexes nearly identical in structure, although stomatal density is noticeably lower in S. alachuense (Figs. 5-8, 5-14). The two species certainly appear closely related, a supposition supported by morphological phylogenetic analysis

(Chapter 3), which indicates that S. tenax and S. alachuense form a clade that is sister to the S. reclinatum complex.

Nomenclatural note. In his protologue for Chrysophyllum carolinense, Jacquin includes a beautiful illustration (1768, Pl. 54) that looks clearly like Sideroxylon tenax, but he makes only brief mention of a specimen: “Sub fructicis Carolinensis titulo a

Sherardo olim in Gronovianum collectionem hoc specimen venit.” Among the specimens imaged from the Sherard Herbarium (OXF) is one from South Carolina, M.

Catesby s.n., that looks very much like Jacquin’s illustration. The original label reads simply, “a kind of thorn which it produces, these have none. Sent from South Carolina by M. Catesby.” It is filed under Bumelia lanuginosa, but a plant of Sideroxylon tenax having the woolier-trending leaf pubescence could be mistaken for S. lanuginosum. I consider this specimen to be S. tenax (common in coastal S. Carolina), and it resembles Jacquin’s illustration closely enough to allow its selection as the lectotype of

Chrysophyllum carolinense Jacq.

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4. Sideroxylon alachuense L.C. Anderson, Sida 17(3): 565–567. 1997. Bumelia lanuginosa (Michx.) Pers. var. anomala Sarg., J. Arnold Arbor. 2:168. 1921. Bumelia anomala (Sarg.) Clark, Ann. Missouri Bot. Gard. 29:169. 1942. Bumelia tenax forma anomala (Sarg.) Cronq., J. Arnold Arbor. 26:456. 1945. (Non Sideroxylon anomalum (Urban) T.D. Pennington, Fl. Neotropica Monogr. 52:123. 1990). TYPE: FLORIDA. ALACHUA COUNTY: Gainesville, 17 Jun 1917, T.G. Harbison 47 (HOLOTYPE: A–internet image!; ISOTYPE: A–internet image!).

Small tree to ca. 9 m tall, trunk diameter to 16.8 cm; young plants often growing in clonal patches as strongly stoloniferous shrubs. Indumentum of unicellular, silver- white to very light golden T-shaped trichomes, symmetric or asymmetric, the trichomes terete and hollow in cross-section, having a short stalk, and a longer top portion of varying length, the top portion straight to slightly curved. Vegetative buds sparsely pubescent with short, appressed trichomes, the stalk 0.03 mm, top 0.2–0.8 mm, the shortest trichomes brown, longer trichomes white. Young twigs (long shoots) terete,

1.3–2.6 mm wide, glabrous or with very few widely scattered pale trichomes and becoming glabrous, smooth, green to greenish-white, becoming cream-white to pale gray, prominently dotted with lenticels, and bearing short, fine longitudinal fissures that lengthen with age of twig; thorns often present at nodes, thorns 0.6–1 (–2) cm long, some becoming short spur shoots or lengthening to become side branches. Mature twigs glabrous, the smooth, pale outer surface becoming mottled tan and light gray, with longitudinal fissures, prominently dotted with lenticels, bearing short spur shoots

(brachyblasts) at nodes, internode length 11–32 mm, older twigs and branches often heavily licheniferous. Leaves tardily deciduous, alternate and spirally arranged on young long shoots, becoming fascicled on brachyblasts on older stems, petioles canaliculate, 4–6 (–7) mm long on young long shoots, 2–5 (–7) mm long on short shoots, and sparsely strigose, becoming glabrous; leaf blades on young long shoots

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36–58 mm long, 15–31 mm wide, broadly ovate-elliptic to elliptic to broadly obovate to rhombic, blades on short shoots 20–50 (–69) mm long, 11–22 mm wide, oblanceolate to elliptic to suborbicular, flat to slightly V-infolded along midvein, coriaceous, the apex acute to rounded to emarginate, the base acute to cuneate, the margin entire and slightly revolute; venation conspicuously finely reticulate, the primary venation pinnate, the secondary venation brochidodromous, with secondary veins slightly decurrent, branching off midvein in opposite to subopposite to alternate arrangement, ± in 6–12 irregularly spaced pairs, with an intersecondary vein occasionally occurring between secondaries, its length ca. 50% the length of the secondaries, its distal course reticulating, the tertiary and quaternary veins irregular-reticulate, the quinternary veins irregular-reticulate to freely ramifying, areolation moderately developed, the marginal ultimate venation looped; adaxial surface dark green, glossy, glabrous, the midvein impressed, higher-order veins slightly impressed to slightly raised (fresh leaf) to conspicuously raised (dried leaf); abaxial surface with dense, persistent, sericeous indumentum of silver-white to light golden T-shaped trichomes, with stalk 0.015–0.05 mm long, top portion 0.4–1.3 mm long, the top portions straight, appressed, multi- layered, and co-oriented ± parallel to the secondary veins, the indumentum appearing lustrous and silky, and completely obscuring the leaf surface, with only the midvein, secondary veins, and some tertiary veins raised and thereby evident; stomata (Fig. 5-

14) recessed inside dome-like chambers raised from leaf surface, the chamber openings round to broadly elliptic, each opening centered in the cup-shaped surface of a raised, broad donut-shaped complex of irregularly concentric cuticular ridges that form a shallow bowl with the opening in the center, the guard cells clearly visible through the

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opening, the surface between stomata smooth and irregularly undulating, epidermal cell boundaries generally not evident. Inflorescence a fascicle borne in a leaf axil, fascicles often tightly clustered on short spur shoots in axils of fallen leaves, each cluster having

3–20 pedicellate flowers, the pedicels 2.5–5 (–6) mm long (mean = 3.8 mm), 0.4–0.5 mm wide, persistently pubescent with dense, sericeous indumentum of silvery-white to light golden straight, appressed, T-shaped trichomes. Calyx of 5 (–6) quincuncial, free sepals, the outer two sepals 1.8–2.3 mm long, 1.8–2.3 mm wide, orbicular, the apex rounded, the margin erose, with a narrow membranous rim, the inner three sepals 2–2.5 mm long, 2–2.5 mm wide, suborbicular, the apex rounded (occasionally retuse), the margin erose, with a broad membranous rim, all sepals persistently pubescent with a dense, shaggy-strigose indumentum of silvery-white to very light golden, straight, appressed to ascending, T-shaped trichomes. Corolla cyathiform, sympetalous, the tube

1–1.6 mm long, enclosed within the calyx; the lobes 5, exserted and spreading, glabrous, white, each with a median lobe and two lateral segments, the median lobe

1.2–1.6 mm long, 1.2–1.6 mm wide, orbicular, clawed, cupped around a stamen, the lateral segments 1.5–2.1 mm long (from junction with adjacent lateral segment), 1.2–1.5 mm long (from junction with median lobe), 0.5–0.7 mm wide, lanceolate; margins erose, translucent. Stamens 5, epipetalous, opposite the corolla lobes, exserted; the filament

1.3–1.6 mm long, 0.2–0.4 mm wide, fixed at top of corolla tube, dilated proximally and narrowing toward anther attachment; the anther 1–1.2 mm long, sagittate, ventrifixed near the point of the sinus, extrorse, opening by two dorsal longitudinal slits.

Staminodes petaloid, alternating with stamens, each staminode 1.7–1.9 mm long, equaling or sometimes exceeding the median corolla lobes, 1.1–1.2 mm wide, ovate-

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deltoid to lanceolate, infolded, base occasionally reflexed; margin erose, translucent.

Ovary superior, 1–1.2 mm long, 1–1.2 mm wide, ovoid to subglobose, tapering abruptly to style, pubescent at anthesis with dense, sericeous indumentum of straight, appressed, white to very light golden T-shaped trichomes, the trichomes longer on distal part of ovary. Style 1–1.4 mm long, glabrous, included. Fruit a single-seeded berry

(rarely 2-seeded), 8.9–13 mm long, 9.2–12.5 mm wide, subglobose, black, glossy, glabrous except for a few scattered trichomes distally. Seeds 8.1–10 mm long, 5.2–7.3 mm wide, ellipsoid; testa hard, smooth, glossy, light brown mottled with cream-white spots; the hilum scar basal, usually bipartite, one part containing the funiculus and usually larger, generally half-moon shaped, 1.8–2.7 mm long, 2.2–3.2 mm wide, and a usually smaller, laterally elongate part abaxial to first part, generally curved or v-shaped,

3–3.6 mm long, 1–2 mm wide, the two parts separated by a bridge of testa, the scar being the exposed portion of a hollow cavity under the testa extending a small distance around the basal end of the seed, the cavity filled, especially on the abaxial side, with a yellowish fatty substance. (See Fig. 5-15.)

Phenology. Flowering mid-June to late July, fruit ripening August and

September.

Distribution and habitat. The largest population of Sideroxylon alachuense occurs in Alachua County, Florida, the namesake of the species, where it is restricted to the area near Alachua Sink in Payne’s Prairie State Park. This area features a mesic calcareous hardwood hammock on rolling sinkhole terrain with limestone outcrops, and an ecotone between hammock and prairie. Sideroxylon alachuense occurs as scattered individuals in the forest understory, and along forest edges and old fencerows

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throughout this localized area. The species also occurs sparingly at a few disjunct locations in Marion, Lake, and Orange Counties (Fig. 5-16). It should be noted that the voucher for Orange County, T.G. Harbison 51 (A), gives the location only as “near

Orlando”; I here assume that it is from Orange County, and I include this county in the species range.

Conservation status. Listed as endangered by the State of Florida.

Illustrations. Godfrey (1988), Fig. 317, by Melanie Darst.

Specimens Examined. USA. Florida. Alachua Co.: Gainesville, 1122 SW 11th

Ave., Anderson 18938 (FSU); Payne's Prairie State Park, fenceline and old railroad bed near bike trail, and entrance road, Alachua Sink area, 1 Jul 2010, 19.60949°N,

082.30509°W, Corogin 1032 (FLAS); ibid., 29.61020°N, 082.30553°W, Corogin 1033

(FLAS); ibid., 29.61139°N, 082.30635°W, Corogin 1035 (FLAS); ibid., 29.60894°N,

082.30421°W, Corogin 1036 (FLAS); ibid., 29.60878°N, 082.30441°W, Corogin 1037

(FLAS); ibid., 29.60857°N, 082.30417°W, Corogin 1038 (FLAS); ibid., 29.60810°N,

082.30332°W, Corogin 1039 (FLAS); ibid., 29°36'31.6"N, 082°18'11.0"W, Corogin 1040

(FLAS); Payne's Prairie State Park, upland near Alachua Sink, 29°36'28.0"N,

082°18'00.9"W, 28 Aug 2012, Corogin 1149 (FLAS); Payne's Prairie State Park, near

Alachua Sink, Godfrey 81389 (FSU); Payne's Prairie State Park, T10S, R20E, S22, near Alachua Sink, north of office building, Herring 1236 (FLAS); Payne's Prairie State

Park, near Alachua Sink, Judd 2824 (FLAS). Lake Co.: Ferndale Preserve,

28°37'24.9"N, 081°41'34.9"W, 9 Aug 2012, Corogin 1122 (FLAS); Ferndale Preserve,

28.623602N 81.693007W, Gulledge 1100 (FSU); near Orlando, 11 Nov 1917, Harbison

51 (A). Marion Co.: Along Silver River, downstream from Silver Springs, south of State

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Road 40, Simons s.n. (FSU). Orange Co.: Upland woods about springs, near Orlando,

11 Nov 1917, Harbison 51 (A).

Discussion. Originally described by Sargent (1921) as Bumelia lanuginosa

(Michx.) Pers. var. anomala Sarg., this unique taxon was elevated to species rank by

Clark (1942) as B. anomala (Sarg.) Clark. Cronquist (1945) renamed it as Bumelia tenax (L.) Willd. forma anomala (Sarg.) Cronquist, associating it with Sideroxylon tenax, with which it shares a silky-sericeous abaxial leaf indumentum, and to which it is closely related (see Chapter 3). Godfrey (1988) recognized it as B. anomala (Sarg.) Clark, and

Anderson (1997) agreed that it is distinctive enough to warrant recognition as a species.

However, the epithet anomalum was preoccupied by Pennington’s (1990) combination

Sideroxylon anomalum (Urban) T.D Penn., referring to a species in the Dominican

Republic, so he gave it the name Sideroxylon alachuense, after Alachua Sink in

Alachua County, Florida, the location of the type collection and the largest known population of this rare species.

Sideroxylon alachuense has sometimes been considered conspecific with S. tenax. The leaves of both entities have a dense, sericeous pubescence on the abaxial leaf surface, and thus can look quite similar. In S. tenax, this pubescence varies in color from dark red-brown to tawny to almost silvery-white (Fig. 5-13). On this basis, several specimens with nearly silvery-white (very slightly tawny) pubescence from coastal locations in northeast Florida and southeast Georgia have been identified as S. alachuense, and distribution maps for this species commonly show this. However, these specimens also have young twigs that are dark-colored and densely rusty-pubescent, which are characteristic of S. tenax (See Fig. 5-10). Plants of coastal northeast Florida

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and southeast Georgia, with silvery leaf indumentum but with pubescent and dark colored young twigs, are not S. alachuense; they are S. tenax. Young twigs of S. alachuense are pale green to cream-white in color, and glabrous (Figs. 5-13, 5-15). On this basis, S. alachuense is thus readily distinguishable from S. tenax. The habitat preference of S. alachuense, mesic calcareous hardwood hammock, also contrasts with that of S. tenax, which prefers xeric sandy environments such as beach dunes and upland scrubs (see also Chapter 4). Sideroxylon alachuense can be considered a narrowly endemic species, restricted to just four counties in north central Florida.

Morphological phylogenetic analysis (Chapter 3) supports a close relationship between this species and S. tenax. The two species share leaf indumentum with trichomes appressed, co-oriented, and multi-layered, completely obscuring the leaf surface, and stomatal complexes nearly identical in structure, although stomatal density is noticeably lower in S. alachuense (Figs. 5-8, 5-14). They form a clade that is sister to a clade containing S. lanuginosum and the S. reclinatum complex. Chloroplast DNA analysis

(Chapter 3) gives an alternative grouping of S. alachuense + S. lycioides.

Nomenclatural note. Sargent (1921) erroneously listed the type collection as being from Hancock County, which does not exist in Florida. It is from Alachua County,

FL.

5. Sideroxylon lanuginosum Michx., Fl. Bor.-Amer. 1:122. 1803.

Shrub, or more often a small tree, 1–15 (–20) m tall, trunk diameter 3–30 cm, the bark of older trunks grey-brown to grey, developing prominent longitudinal red-orange tinted fissures, sometimes also with short transverse fissures, plants not strongly stoloniferous. Indumentum of unicellular, red-brown to light brown to grey to white T-

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shaped trichomes, symmetric or asymmetric, terete and hollow to flattened in cross- section, having a short stalk and a longer upper portion of varying length, the upper portions straight to bent and curled, nearly always ascending (sometimes appressed).

Vegetative buds densely wooly-pubescent with short, nearly sessile, appressed to ascending, bent and curled, dark red-brown T-shaped trichomes, the stalk 0.01–0.03 mm long, the upper portion 0.2–0.4 mm long. Young twigs (long shoots) 1–1.4 mm wide, terete, moderately to densely wooly to shaggy-strigose with red-brown to light brown to grey to white T-shaped trichomes, the trichomes with stalk 0.02–0.15 mm long, upper portion 0.5–1.6 mm long, the top portions mostly flattened in cross section and twisted, sometimes terete, straight to bent and curled, often markedly asymmetrical, appressed to ascending, the pubescence often persisting into the second season, the twig surface smooth, green to dark red-brown, prominently dotted with lenticels; thorns often present at nodes, especially on younger stems, thorns 1–10 cm long, occasionally lengthening to become side branches. Mature twigs sometimes persistently pubescent, becoming glabrous, the surface dark red-brown becoming gray-brown to grey, lenticels still evident, surface remaining smooth or becoming longitudinally fissured with age, the twigs bearing short spur shoots (brachyblasts) at nodes, which after many seasons will occasionally lengthen into long shoots, internode length 12–42 mm. Leaves tardily deciduous (fully deciduous in the colder parts of the species range), alternate and spirally arranged on young long shoots, becoming fascicled on brachyblasts on older stems, petioles 2–15 (–17) mm long, canaliculate, and densely to sparsely wooly or shaggy-strigose to glabrous, the T-shaped trichomes red-brown to light brown to grey to white, petioles often becoming glabrate with age; leaf blades highly variable in size on

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same plant and from one plant to another, often larger on young long shoots than on short shoots, 1–10 (–13) cm long, 0.5–4 (–6) cm wide, oblanceolate to broadly obovate to elliptic, coriaceous, the apex rounded to bluntly acute, occasionally retuse, rarely sharply pointed, the base cuneate to acute, often slightly concave, the margin entire, blades of mature leaves flat; venation pinnate and visibly finely reticulate, major secondaries brochidodromous, or occasionally eucamptodromous becoming brochidodromous distally, with secondary veins slightly decurrent, branching off midvein in opposite to alternate arrangement, ± in 4–8 (–12) irregularly spaced pairs, with an intersecondary vein occasionally occurring between secondaries, the tertiary veins irregular-reticulate, the quaternary veins irregular-reticulate, the quinternary veins irregular-reticulate to freely ramifying, areolation moderately developed, the marginal ultimate venation looped; adaxial surface green, semi-glossy to dull, sometimes loosely wooly-pubescent when young, becoming glabrous with age except perhaps along the midvein, the major veins conspicuous, the tertiary vein reticulum evident, sometimes boldly conspicuous, the veins impressed to flush on fresh leaves, raised on dried specimens, the surface faintly to strongly veiny-textured; abaxial surface with indumentum varying from moderately densely, evenly, and persistently pubescent to nearly glabrous, the pubescence loosely wooly to matted-wooly and varying from red- brown to light brown to grey to white, the T-shaped trichomes mostly terete

(occasionally flattened) in cross-section, the stalk 0.07–0.25 mm long, the upper portion

0.5–2 mm long, the upper portions mostly bent and curled (some straight), appressed to ascending, the leaf surface visible, never obscured by pubescence, most veins evident, raised, the midvein and secondaries prominent; stomata (Fig. 5-17) recessed inside

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dome-like chambers raised slightly from leaf surface, the chamber openings elliptic and thick-rimmed, each opening encircled by a broad donut-shaped complex of irregularly concentric epicuticular ridges, the rim of the opening flush with or higher than the surrounding ridges, the guard cells clearly visible through the opening, the surface between stomatal complexes smooth and undulating to strongly patterned with ridges and grooves that generally follow epidermal cell boundaries. Inflorescence a fascicle borne in a leaf axil, fascicles often clustered on short spur shoots in axils of fallen leaves, each cluster having 6–20 (–35) pedicellate flowers, the pedicels (2–) 4–12 (–15) mm long, glabrous to densely and persistently wooly or shaggy-strigose, the trichomes red-brown to light brown to grey to white, pedicels sometimes becoming glabrate with age. Calyx of 5 (–6) quincuncial, free sepals, the outer two sepals 1.5–3 mm long, 1.8–3 mm wide, suborbicular to broadly ovate to reniform, the apex rounded, the margin entire, usually with a narrow membranous rim, the inner three sepals (1.5–) 2.2–3 mm long, 2.1–3 mm wide, ovate to suborbicular to reniform, the apex rounded to retuse, the margin entire to erose, with a broad membranous rim, all sepals glabrous to densely and persistently wooly or shaggy-strigose, the trichomes red-brown to light brown to grey to white. Corolla white, cyathiform, sympetalous, the tube 1.2–2.5 mm long, enclosed within the calyx; the lobes 5, exserted and spreading, glabrous, each with a median lobe and two lateral segments, the median lobe 1.2–2 mm long, 1–1.7 mm wide, oval to suborbicular, sessile to clawed, cupped around a stamen, the lateral segments 1.5–2.5 mm long (from junction with adjacent lateral segment), 1.2–1.6 mm long (from junction with median lobe), 0.5–1 mm wide, lanceolate, all corolla margins erose. Stamens 5, epipetalous, opposite the corolla lobes, exserted; filament 1.3–2 mm

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long, 0.4 mm wide, fixed at top of corolla tube, dilated proximally and narrowing toward anther attachment; anther 1–1.5 mm long, sagittate, ventrifixed at the point of the sinus, extrorse, opening by two dorsal longitudinal slits. Staminodes petaloid, alternating with stamens, each staminode 1.7–2.3 mm long, 1.2–1.9 mm wide, nearly equaling the length of the median corolla lobes, deltoid to ovate to lanceolate, infolded, the base often reflexed, margin erose, translucent. Ovary superior, 5–(6 –) loculate, locules uniovulate with basal-axile placentation, ovary ca. 0.8–1.3 mm long, 1 mm wide, subglobose to ovoid, tapering abruptly to style, at anthesis densely strigose with pale to light brown T-shaped trichomes, the trichomes longer on distal part of ovary; style 1.3–

1.7 mm long, glabrous, included. Fruit a berry, one (rarely 2)-seeded, 6–12 (–14) mm long, obovoid to ellipsoid to subglobose, often tipped by a persistent style, black, glossy, glabrous. Seeds 6–8 (–11) mm long, 3.8–6 mm wide, oblong-ellipsoid, sometimes with a truncate base, the testa hard, smooth, glossy, the color solid brown to variegated brown and yellow/cream-white; the hilum scar basal, bipartite, the larger part basal, irregularly half-moon shaped to suborbicular, 1–2 mm long, 1–2 mm wide, the smaller part abaxial to the other part, long and narrow, shallowly U-shaped, 1.5–4 mm long,

0.3–1 mm wide, the parts usually well-separated by a bridge of testa but sometimes merging, the scar being the exposed portion of a hollow cavity under the testa extending a small distance around the basal end of the seed, the cavity filled with a yellowish fatty substance. (See Fig. 5-18).

Distribution and habitat. Northern Florida, Georgia, Alabama, Mississippi,

Louisiana, Arkansas, Missouri, southeastern Kansas, Oklahoma and Texas, extending into the northern tier of Mexican states, and westward sparingly into New Mexico and

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southern Arizona (Fig. 5-19). Mesic to dry wooded uplands, river bottomlands, prairie margins, and along mountain streams.

Phenology. Flowering May–July, fruit ripening August–October.

Common names. Chittamwood, gum bully, gum bumelia, gum elastic.

Illustrations. Godfrey (1988, Fig. 318, by Melanie Darst); Lounsberry & Rowan

(1901, p. 423, pl. 135); Sargent (1893, Tab. 247).

Key to the Subspecies of Sideroxylon lanuginosum

1. Largest short-shoot leaves longer than 5 cm; plant often over 8 m tall; Kansas and Oklahoma south to central and eastern Texas, east through Missouri, Arkansas, Louisiana, Mississippi and Alabama to Florida and Georgia ------2

2. Pubescence of leaves red-brown to light brown to grey, moderately dense to sparse, wooly, the trichomes curled; Kansas and Oklahoma south to central and eastern Texas, east through Missouri, Arkansas, Louisiana, Mississippi and Alabama to Florida and Georgia ------subsp. lanuginosum

2. Pubescence of leaves white, dense, wooly but matted, many of the trichomes straight and appressed; southeastern to central Texas and extreme northeastern Mexico ------subsp. albicans

1. Largest short-shoot leaves less than 5 cm long; plant typically less than 8 m tall; southwestern Oklahoma, central Texas west to southern New Mexico and Arizona, and the northern tier of states in Mexico ------subsp. rigidum

Sideroxylon lanuginosum Michx. subsp. albicans (Sarg.) Kartesz & Gandhi, Phytologia 68:425. 1990. Bumelia lanuginosa (Michx.) Pers. var. albicans Sarg., J. Arnold Arbor. 2:168. 1921. Bumelia lanuginosa (Michx.) Pers. subsp. albicans (Sarg.) E. Murray, Kalmia 13:4. 1983. TYPE: USA. TEXAS. VICTORIA CO.: Guadalupe River bottoms, near Victoria, 9 Apr 1915, C.S. Sargent s.n. (HOLOTYPE: A #00075469–internet image!).

Small tree to 20 m tall. Indumentum white to grey-white, the trichomes generally longer and straighter and more appressed than in the other two subspecies. Young twigs (long shoots) densely wooly to shaggy-strigose, the T-shaped trichomes white to grey-white, thorns often present at nodes. Mature twigs glabrous, dark brown to grey brown, becoming grey, internode length 12–42 mm. Leaves with petioles 6–17 mm

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long, petioles densely shaggy-strigose, the trichomes white; leaf blades 4–7 cm long, 1–

2.8 cm wide, oblanceolate to oblong-elliptic, the apex rounded, the base cuneate to acute; secondary venation brochidodromous, the major secondaries branching off midvein in 6–10 irregularly spaced pairs; adaxial surface semi-glossy, sometimes loosely wooly-pubescent when young, becoming glabrous with age except perhaps along the midvein, the vein reticulum evident, major veins conspicuous; abaxial surface with dense, persistent, matted wooly indumentum, the T-shaped trichomes white, the stalk 0.1–0.25 mm long, the upper portion 0.8–2 mm long, the upper portions straight to bent, appressed to ascending, most veins evident, the midvein and secondaries raised and prominent. Pedicels 6–16 mm long, densely shaggy-strigose with conspicuously spreading blonde to white trichomes. Outer sepals 2–3 mm long, 2.5–3 mm wide, suborbicular to reniform, the inner sepals 2.8–3 mm long, 2.8–3 mm wide, suborbicular to reniform, all sepals densely to sparsely and persistently shaggy-strigose, the trichomes white to light brown. Corolla tube 1.7–2.5 mm long. Staminodes deltoid, the base strongly reflexed. Ovary densely strigose, trichomes longer distally.

Distribution and habitat. Southeastern to central Texas, south to Nuevo Leon in northeastern Mexico (Fig. 5-19). River bottomlands, terraces above streams, prairie ravines, fencerows.

Specimens examined. USA. Texas. Aransas Co.: Aransas Refuge, E of

Tomas well along shell ridge, 7 Aug 1939, Uzzell 152 (US). Austin Co.: Hwy 36, 7.1 mi

N of its jct with Hwy 949 at Bellville, 3 Apr 1999, Smith 35 (LSU). Bexar Co.: San

Antonio, 20 Sep 1939, Clark 567 (FLAS, GH, US). Brazoria Co.: Columbia, 15 Oct

1900, Bush 1524 (A). Columbia, 22 Sep 1901, Bush 877 (A); Columbia, 30 Mar 1914,

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Palmer 5050 (A). Brazos Co.: Along streams, Bryan, 30 Apr 1917, Palmer 11739 (US). near Neleva, 24 Apr 1918, Palmer 13446 (A, US). Burnet Co.: Along river, Marble

Falls, 29 Jun 1903, Biltmore 1688 (US). Calhoun Co.: Indianola, 11 Oct 1934, Cory

11618 (A). Coryell Co.: On TX 116, 8 mi S of Gatesville and 5 mi N of Pidcoke, 25 Apr

1974, Hess 3144 (OKL). Dallas Co.: Dallas, Jul 1874, Reverchon 384 (GH); Turtle

Creek and Stonebridge Drive, Dallas, 9 Oct 1948, Shinners 10579 (GA). Dimmit Co.:

Carrizo Springs, 4 May 1928, Palmer 33735 (A). Fayette Co.: Scenic overlook along westbound TX Hwy 71, ca. 1 mi E of Fayette Co. Rd 118, just E of Kirtley, just E of

Fayette-Bastrop Co. line, 23 Jun 1991, Lievens 4903 (LSU). Fort Bend Co.: Railroad right-of-way off US 59, ca. 0.5 mi N of Darst & Kendleton City limits, 27 Jul 1984,

Whetstone & Nixon 14621 (USF). Goliad Co.: Sandhills near San Antonio River, Mulley

Pasture, Fant Ranch, ca. 5 mi SE of Goliad, 30 Jul 1987, Hill 18419 (GH; USF).

Gonzales Co.: Ottine Swamp, 30 Apr 1933, Cory 5770 (A). Guadalupe Co.:

Comanche Spring, New Braunfels, Jul 1850, Lindheimer 979 (GH, OKL, US). Harris

Co.: Houston, 18 Jun 1915, Fisher 1531 (US). Matagorda Co.: Peyton’s Creek, 12 May

1916, Palmer 9734 (A). Nueces Co.: Bluffs, Nuecestown, 27 Apr 1896, Marlatt s.n.

(US). San Patricio Co.: Welder Wildlife Foundation, N of Sinton, 150 m E of house at

Moody’s Camp, 4 May 1959, Traverse 1210 (US). Travis Co.: Austin, 1881, Buckley s.n. (US); Austin, 3 Oct 1936, Tharp 8269 (A, FLAS). Victoria Co.: Victoria, 7 Mar

1916, Palmer 9104 (A). Wharton Co.: Alluvial banks, Colorado River, Wharton, 10 Mar

1914, Palmer 4902 (A). Wilson Co.: Southerland Springs, 17 Mar 1916, Palmer 9209

(A); Sutherland Springs, 8 Apr 1915, Sargent s.n. (A). Mexico. Nuevo Leon: By streams of mountains near Monterey, 9 Jun 1889, Pringle 2413 (A, GH, US).

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Sideroxylon lanuginosum Michx. subsp. lanuginosum, Fl. Bor.-Amer. 1:122. 1803. Bumelia lanuginosa (Michx.) Pers., Syn. Pl. 1:237. 1805. Lyciodes lanuginosum (Michx.) Kuntze, Revis. Gen. Pl. 2: 406. 1891. TYPE: USA. GEORGIA: Without data, Michaux s.n. (HOLOTYPE: P #P00644529–internet image!; ISOTYPE: GH #00075467–internet image!).

Chrysophyllum ludovicianum Raf., Fl. Ludov. 53. 1817. TYPE: USA. LOUISIANA. IBERIA PARISH: Wooded loess ravine on Avery Island salt dome, 11 Apr 1983, Givens 2949 (NEOTYPE here selected: LSU #59617!).

Bumelia oblongifolia Nutt., Gen. N. Amer. Pl. 1:135. 1818. Bumelia lanuginosa (Michx.) Pers. var. oblongifolia (Nutt.) R.B. Clark, Ann. Missouri Bot. Gard. 29:163. 1942. Bumelia lanuginosa (Michx.) Pers. subsp. oblongifolia (Nutt.) Cronquist, J. Arnold Arbor. 26:453. 1945. Sideroxylon lanuginosum Michx. subsp. oblongifolium (Nutt.) T.D. Penn., Fl. Neotrop. Monogr. 52:169. 1990. Sideroxylon lanuginosum Michx. var. oblongifolium (Nutt.) B.L. Turner, Sida, Bot. Misc. 24:8. 2003. TYPE: USA. ARKANSAS: Without data, T. Nuttall s.n. (HOLOTYPE: PH #00025208, fragment “C” on sheet–internet image!; ISOTYPE: BM, #BM000839937–internet image!).

Bumelia arachnoidea Raf., New Fl. 3:28. 1836. TYPE: USA. ARKANSAS AND TEXAS, not seen.

Bumelia rufa Raf., New Fl. 3: 29. 1836. TYPE: USA. FLORIDA: Ware s.n. (not seen).

Tatina parviflora Raf., Autik. Bot.: 75. 1840. TYPE: USA. MISSISSIPPI: Near Natchez, 1820, Hart s.n. (not seen).

Bumelia tomentosa A.DC., Prodr. (A.P. de Candolle) 8:190. 1844. TYPE: USA: Without data, “Bumelia oblongifolia herb. Dawes…,” Anon. s.n. (LECTOTYPE here selected: G-DC #G00139953–internet image!)

Bumelia ferruginea Nutt, N. Amer. Sylva 3: 34. 1849. TYPE: USA. FLORIDA: “W Florida”, without date, Ware s.n. (HOLOTYPE: PH #00025207, fragment “A” on sheet–internet image!).

Bumelia arborea Buckley, Proc. Acad. Nat. Sci. Philadelphia 13:461. 1862. TYPE: USA. TEXAS: “Southern Texas”, without date, S.B. Buckley s.n. (HOLOTYPE: PH, #00025209, fragment “B” on sheet–internet image!).

Shrub or often a small tree, 1–15 m tall. Indumentum red-brown to light brown to grey, the trichomes bent and curled, occasionally straight, ascending. Young twigs (long shoots) moderately to densely wooly to shaggy-strigose, the T-shaped trichomes red-

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brown to light brown to grey, pubescence persisting through first season and sometimes longer, thorns often present at nodes. Mature twigs sometimes persistently pubescent, becoming glabrous, internode length 12–42 mm. Leaves with petioles 2–15 mm long, petioles densely to sparsely wooly or shaggy-strigose, the trichomes red-brown to light brown to grey; leaf blades 2–10 (–13) cm long, 1–4 cm wide, oblanceolate to broadly obovate to elliptic, the apex rounded to bluntly acute, the base cuneate to acute; secondary venation brochidodromous, or occasionally eucamptodromous becoming brochidodromous distally, the major secondaries branching off midvein in 6–8 (–12) irregularly spaced pairs; adaxial surface semi-glossy, sometimes loosely wooly- pubescent when young, becoming glabrous with age except perhaps along the midvein, the vein reticulum evident, major veins conspicuous; abaxial surface with generally persistent, loosely wooly indumentum varying from moderately dense to sparse, the T- shaped trichomes red-brown to light brown to grey, with stalk 0.07–0.15 mm long, top portion 0.5–1.6 mm long, the upper portions bent and curled (sometimes straight), ascending, the midvein and secondaries prominent. Pedicels 4–12 (–15) mm long, with generally persistent, moderately dense to sparse, shaggy-strigose indumentum, the trichomes red-brown to light brown to grey. Outer sepals 1.7–2.5 mm long, 1.8–2.5 mm wide, suborbicular to broadly ovate, the inner sepals 2.2–2.5 mm long, 2.1–2.5 mm wide, ovate to suborbicular, all sepals densely to sparsely and persistently wooly or shaggy-strigose, the trichomes red-brown to light brown to grey. Corolla tube 1.2–2 mm long. Staminodes deltoid to ovate to lanceolate, the base often reflexed. Ovary densely strigose, trichomes longer distally. (See Fig. 5-18).

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Distribution and habitat. Northern Florida, Georgia, Alabama, Mississippi,

Louisiana, Arkansas, Missouri, southeastern Kansas, Oklahoma and eastern to central

Texas (Fig. 5-19). Mesic to dry wooded uplands, river bottomlands, prairie margins, elevation below 450 m.

Specimens examined. USA. Alabama. Autauga Co.: House Bluff, on E shore of Alabama River, ca. 1 mi due SW of Cedar Grove Church, near Autaugaville, T17N,

R13E, Sec. 35, 7 Sep 1982, Gunn 1164 (AUA). Baldwin Co.: Behind sports complex at jct of Canal Rd and Ken Shivers Rd, between Orange Beach and Gulf Shores,

30°16’33”N, 87°38’37”W, 8 Jun 2006, (UNA). Bibb Co.: Reed Brake Research Natural

Area, Ocmulgee Division, Talladega National Forest, 14 Sep 1981, Golden s.n. (AUA).

Bullock Co.: High ridge, dirt rd, 0.2 mi E of County Hwy 7, T13N, R21E, Sec 36, 31 Jul

1988, Diamond 5340 (AUA). Chilton Co.: White Oak Valley Plantation, un-numbered dirt rd NW of Cobb Creek, 33°02’39”N, 86°42’40”W, Ozan Quad, 16 Jun 2005, Diamond

15475 (AUA). Clarke Co.: 4 air mi SE of Whatley, along US 84 ca. 1.5 mi E of jct with

County Rd 35, 31°37’30”N, 87°38’46”W, 3 Jun 2007, Keener 3661 (UNA). Coffee Co.:

Vicinity of Kingston, along Hwy 474 (Hwy 6 on old map), 0.1–0.3 mi W of jct with Pea

River, 2 Jan 1999, MacDonald 12515 (UNA). Conecuh Co.: Sepulga River where crossed by dirt rd from Paul, near bridge, 31 Aug 1986, Diamond 2774 (AUA). Dale

Co.: US Hwy 231, S side of Choctawhatchee River, S side of rd, T4N, R25E, Sec 5, 19

Jul 1989, Diamond 5957 (AUA). Coosa Co.: Gneissic bluff above AL 22 just E of Coosa

River, below Mitchell Dam, 27 Jun 1977, Kral 60488 (TENN). Dallas Co.: Thatcher’s

Bluff, Six Mile Creek (bluff of Alabama River), 27 Jun 1964, Demaree 50602 (AUA).

Geneva Co.: W bank of Choctawhatchee River where Hwy 52 crosses, T1N, R22E,

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Sec 21, SW quarter, 26 Nov 1999, MacDonald 13734 (MISS). Hale Co.: Okmulgee

National Forest, nature trail at N end of pine ridges, T22N, R6E, Sec 11, 5 Sep 1993,

Diamond 8767 (AUA). Henry Co.: Abbeville, 10 Jun 1911, Howell 774 (US). Houston

Co.: Ca. 2.5 mi SE of Gordon, McCallister farm, T2N, R30E, NE ¼ of NE ¼, 14 Mar

1997, MacDonald 10021 (MISS). Lee Co.: Along Turkey Creek, 1.5 mi N of Smith’s

Station and 18 mi E of Opelika, 7 Apr 1949, Duncan 9213 (UNA). Lowndes Co.: Blue

Bluff, at Corps of Engineers’ Holy Ground Battlefield Park, on S shore of Alabama River, ca. 2.25 mi NE of Whitehall, T16N, R14E, Secs 19 & 20, 6 Sep 1982, Gunn 1120

(AUA). Monroe Co.: 5.5 air mi SW of Perdue Hill, along County Rd 1 ca. 6 mi S of

Perdue Hill, 31°26’49”N, 87°32’32”W, 3 Jun 2007, Keener 3667 (UNA). Pike Co.: Un- numbered dirt rd, 0.2 mi S of County Hwy 26, T10N, R22E, Sec 6, 30 Aug 1988,

Diamond 5450 (AUA). Russell Co.: Near Phoenix City, 16 Sep 1902, Biltmore 1688n

(US). Wilcox Co.: Prairie Bluff, on W shore of Alabama River, ca. 3.25 mi N of Miller’s

Ferry Dam, near Prairie Mission, T14N, R7E, Sec 32, 9 Sep 1982, Gunn 1257 (AUA).

Arkansas. Ashley Co.: Roadsides E of Fountain Hill, Sec. 1, T16S, R7W, 12 Jun 1985,

Thomas 92619 (TENN). Benton Co.: Near Monte Ne, 9 May 1924, Palmer 24749 (A).

Boone Co.: Harrison, 25 Oct 1914, Palmer 6917 (A). Bradley Co.: Warren, 22 May

1943, Demaree 24439 (OKL); Warren, 13 Jun 1944, Demaree 25032 (GH). Carroll Co.:

Beaver, 22 Jul 1914, Palmer 6330 (A). Clark Co.: Arkadelphia, 20 Jul 1916, Palmer

10536 (A). Conway Co.: Petit Jean State Park, Petit Jean Mtn, 10 Aug 1954, Moore 91

(TENN). Drew Co.: Knolls in prairies, Wilmar, 11 Sep 1943, Demaree 24627 (GH).

Faulkner Co.: Ravine N of Conway, 16 Sep 1934, Ford 111 (FLAS). Garland Co.:

Along creeks near Hot Springs, 5 Jun 1923, Palmer 23083 (A). Hot Spring Co.: Rocky

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bottoms, Butterfield, 23 Jul 1955, Demaree 37572 (GH). Malvern, Social Hill, 9 May

1967, Demaree 55685 (AUA). Independence Co.: Near Foshee Cave, 3 mi N of Locust

Grove on AR 25, 24 Jul 1969, Thomas 15581 (TENN). Izard Co.: Devil’s Backbone

Natural Area, from Mt. Olive Rd entrance at sign, 1 mi N of jct with Hwy 9, 9 air mi N of

Mtn View, T16N, R10W, S27, S ½, 30 May 2002, Nunn 5725 (OKL). Jackson Co.:

Newport, 7 May 1881, Letterman s.n. (A). Lawrence Co.: Strawberry, 12 Jul 1947,

Demaree 26195 (OKL). Logan Co.: Top of Magazine Mtn, 17 Oct 1923, Palmer 24165

(A); ca. 5 mi SE of Paris, Sec 21, T7N, R25W, 7 Jul 1965, Redfearn 17307 (GA).

Marion Co.: Bluffs of White River, Cotter, 11 Jun 1914, Palmer 5915 (FSU). Miller Co.:

Doddridge, near fire tower, 15 Jun 1972, Demaree 65172 (FLAS). Newton Co.:

Compton, 27 Aug 1955, Demaree 38215 (OKL). Pike Co.: Daisy, Near Lake Greeson,

14 May 1955, Demaree 36775 (OKL). Polk Co.: Sugar Creek Vista, FS Rd 38, 1.5 mi S of FS Rd 25, SW Sec 1, T4S, R29W, 23 May 1999, Kral 88557 (FSU). Pope Co.:

Hector, foothills of Ozarks, 17 Oct 1932, Merrill 88 (A). Pulaski Co.: North Little Rock,

31 Jul 1955, Demaree 37714 (OKL). Randolph Co.: Maynard, 10 Jul 1939, Bishop s.n.

(OKL). Saline Co.: Road bank and woods beside Dobbs Creek at AR 229 and US 67 at

I-30 SW of Benton, Sec. 17, 12 May 1996, Thomas & Amason 148806 (TENN). Scott

Co.: Ouachita National Forest, White Oak Mtn, on County Rd 178 of F.R. 20, 10 air mi

NE of Waldron, T4N, R28W, Sec 26, NE ¼, UTM 3871120, 0413766, 29 Jun 2003, Nutt

547 (OKL). Sharp Co.: Hardy, 18 May 1947, Demaree 26068 (OKL). Stone Co.:

Blanchard Spgs, upper campground area, banks of Sylamore Creek between the 2 rd forks, 13 Jul 1969, Browne 6919.6 (TENN). Union Co.: Beside Champagnolle Rd NE of

US 167 and El Dorado, Sec 13, T17S, R15W, 7 Oct 1988, Thomas et al. 108064

150

(TENN). Van Buren Co.: Near Shirley, 23 Oct 1923, Palmer 24314 (A). Florida.

Alachua Co.: Gainesville, Univ. of Florida campus, NW corner of Museum Rd and

Newell Drive, 23 Jun 2009, Corogin 1001 (FLAS). Bradford Co.: 6 mi E of Starke, 12

May 1939, Murrill 521 (US). Calhoun Co.: Ca. 3.5 mi ENE of Blountstown, S36, T1N,

R8W, on natural levee of Apalachicola River, 8 Apr 1967, McDaniel 8729 (FSU). Citrus

Co.: Withlacoochee State Forest, Citrus section, side rd S of Dames Caves. 27 May

1973, Genelle & Fleming 1892 (USF). Clay Co.: S36, SE, T7S, R23E, NW edge of

“ravine and ridge trail” parking lot, 12 Sep 1982, Skean 856 (USF); Gold Head Branch

State Park, Fern Loop fence, E side of SR 21, ca. 10 mi N of Keystone Heights, 20 Aug

1982, White 272 (FLAS). Columbia Co.: Lake City, 17 Apr 1902, McCulloch s.n.

(FLAS). Dixie Co.: On shell mound, tip of Shired Island, ca. 19 mi SSW of Cross City,

S34, T12S, R11E, 28 Jun 1959, Ward 1520 (FLAS). Escambia Co.: Near the coast, 6

Jul 1902, Mohr s.n. (US). Bluff Springs, 12 July 1932, Tisdale s.n. (FLAS). Franklin

Co.: St. Vincent Island, W of Apalachicola, 8 Jun 1983, Judd 3366 (FLAS). Gadsden

Co.: Quincy, 18 Apr 1930, Kincaid & West s.n. (FLAS). Gilchrist Co.: Fanning Springs,

26 Sep 1959, Godfrey 59956 (FSU, GH). Gulf Co.: Shell mound on shore of bay at S end of St. Joseph Peninsula (Richardson Hammock), 9 Oct 1990, Johnson 8769 (GA).

Hamilton Co.: On bench above Alapaha River, 0.5 mi SW of I-75, 5 mi WSW of Jasper,

S17, T1N, R13E, 6 Apr 1972, Ward 8295 (FLAS). Hernando Co.: Ca. 12 mi NW of

Brooksville off US 98, NE portion of old Annultilago Hammock region, 30 Jun 1962, Ray

& Lakela 11102A (USF). Holmes Co.: Above the floodplain of Chocktawhatchee River,

W of Millers Crossroads, by FL Rt 2, 17 Mar 1982, Godfrey 79420 (FSU). Jackson Co.:

By FL Rt 271, N of Sneads, somewhat N of rd leading to Parramore Landing on Lake

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Seminole, 1 May 1982, Godfrey 79745 (FLAS). Jefferson Co.: Big Blue Spring of

Wacissa River, T2N, R3E, NE ¼ of NW ¼, Sec 12, 30 Sep 2002, Anderson 20516

(FSU). Lafayette Co.: At US 27 bridge over Suwannee River, ca. 0.5 mi W of Branford,

T6S, R14E, Sec 20, NE ¼ of NE ¼, 12 Jun 2008, Hansen 13160 (USF). Lake Co.: Just

W of the St. Johns River, ca. 6 mi W of Deland, 4 Apr 1956, Lemaire 500 (FSU). Leon

Co.: Along the Ochlockonee River at Larkin’s Bluff, 8 May 1956, Godfrey 54745 (FLAS).

Levy Co.: Cedar Key, corner of Sherill St and Hodgson Ave, 29.14463°N,

083.05201°W, 26 Aug 2011, Corogin 1057 (FLAS); Manatee Springs State Park, near

Shacklefoot Pond, 19 June 1998, Gulledge 587 (FLAS). Liberty Co.: White Springs, 1

Jun 1963, Godfrey 62844 (FLAS). Marion Co.: Silver River State Park, N of Rt 314, E of Rt 35, T15S, R23E, SW ¼, Sec 8, 12 Jun 1996, Anderson 16587 (FSU). Okaloosa

Co.: Turkey Creek valley, NE of Rt 224, ca. 3 mi E of Niceville, S3, T1S, R22W, 17 Apr

1969, Ward 7157 (FLAS). Pinellas Co.: Boca Ciega Bay, Maximo Point City Park, 16

Jun 1972, Thorne 41909 (FLAS). Putnam Co.: 200 ft E of the Alachua/Putnam county line, ca. 150 ft from S shore of Little Orange Lake, 7 Jun 2006, Bubb s.n.(FLAS).

Suwannee Co.: Ca. 0.28 air mi SW of US 90 at Falmouth, Falmouth Spring, NWQ,

NEQ, NEQ, Sec 32, T1S, R12E, Falmouth 7.5’ Quad, 30°21’37’N, 83°08’05”W, 16 Jul

1990, Orzell & Bridges 14363 (USF). Taylor Co.: Hampton Spring, 9 Apr 1931, Palmer

38474 (A). Wakulla Co.: St. Marks Wildlife Refuge, 21 Jun 1972, Godfrey 71402 (FSU).

Walton Co.: Grayton Beach State Park, along nature trail near the first station, 26 Jun

1981, Wilhelm & Bush 9277 (USF). Georgia. Appling Co.: Ca. 15 mi NE of Baxley on

Rt 144, 19 May 1955, Sargent 7240 (FSU). Baker Co.: Ca. 9 mi NW of Newton, ca.

2.75 mi NNE of Elmodel, just N of Clear Lake Rd (Co. Rd 121) and just E of

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Chickasawhatchee Creek, 23 May 1990, Allison 4463 (GA). Berrien Co.: Margin of a slough lakeof Withlacoochee River on property of Edward Lee, 3 mi NE of the GA

Sherriff’s Boy’s Ranch, 26 Aug 1965, Faircloth 2904 (GA). Brooks Co.: W on Shiloh Rd thru Shiloh dead end, L on Morven Rd, 2.9 mi, E bank of river, 31 May 1986, James 35

(GA). Calhoun Co.: E side of Ichawaynochaway Creek, ca. 3 mi W of Leary, 20 July

1980, Godfrey 77974 (FSU). Candler Co.: 3 mi E of Metter, 24 Aug 1941, Duncan 3968

(FLAS). Coffee Co.: 6.1 mi E of Douglas, 19 May 1953, Duncan 16245 (GA). Decatur

Co.: Floodplain of Flint River at Bainbridge, under overpass of US 27, 11 Sep 1970,

Lazor 4853 (FSU). Dougherty Co.: Dr. Gillespie’s Pocoson place, 1 May 1928,

Gillespie 4956 (A). Early Co.: Behind pond in Kolomoki Mound Park, 5 May 1986,

Churchill 86131 (LSU). Echols Co.: 6 mi S of Stockton at Mayday, at Noseworthy

Farm, 16 May 1962, Faircloth 76 (GA). Evans Co.: N side of Canoochee River, 3.8 mi

NW of Claxton, 3 Apr 1953, Hardin 15106 (GA). Floyd Co.: S side of Coosa River, 3 mi

SW of Rome, 9 Apr 1953, Hardin 15247 (GA). Grady Co.: Rim of Waterfall Limesink,

10 mi N of Whigham, 5 Jul 1963, Durham 355 (GA). Harris Co.: Along Mulberry Creek at Robert Louis Girl Scout Camp, off GA 103, 21 Oct 1972, Jones 22357 (FLAS).

Houston Co.: 0.5 mi S of Perry, 3 Sep 1954, Hardin 18128 (GA). Jefferson Co.: N side of Ogeechee River 1 mi S of Louisville, 20 Apr 1941, Duncan 3191 (GA). Jenkins

Co.: Big Duke’s Pond, 8 Aug 1942, Duncan 5638 (GA). Johnson Co.: Slopes just E of

Ohoopee River, 0.8 mi E of Kite, 27 Mar 1954, Duncan 17527 (GA). Jones Co.: Hitichiti

Experimental Forest, Oconee National Forest, Stand 13 of Compartment 8 on Falling

Creek floodplain, 21 Aug 1999, Sweeney 923 (GA). Lee Co.: N of Starkesville Bridge over Muckalee Creek, 19 May 1940, Duncan 2349 (GA). Lowndes Co.: Sam Cothron

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farm, 12 mi SE of Valdosta, 20 Nov 1963, Faircloth 714 (GA). Mitchell Co.: Old wagon trail, just ENE of Gee Pond on Big Slough, SW Mitchell County, 6 Jul 1968, Hancock 9

(GA). Pierce Co.: N of Satilla, near US 87, 6 Jul 1959, Cypert 213 (GA). Pulaski Co.: 4 mi ESE of Hawkinsville along Limestone Creek, 31 Jul 1953, Harper & Humphrey

16885 (UNA). Randolph Co.: Cuthbert, 7 Nov 1917, Harbison 6 (A). Talbot Co.:4.6 mi

E of Geneva, 30 Jul 1953, Harper et al. 16779 (GA). Taylor Co.: 6 mi S of Butler, 12

Sep 1952, Duncan 13974 (GA). Telfair Co.: 10 mi S of McRae on Rt 441, 22 May 1953,

Wilbur 3342 (FSU). Terrell Co.: Bank of Rinchafoonee Creek, 2 Aug 1901, Harper 1153

(GH). Thomas Co.: Titi Hammock, 31°05’N, 84°20’W, 10-17 May 1991, Quigley 253

(LSU). Toombs Co.: Lyons, 5 Jan 1973, Cave s.n. (GA). Twiggs Co.: Griswoldville

LTA, Ga Pacific Comp. 843A, M.D. Butts Tract, 7 Jun 1996, Govus 772 (GA). Wayne

Co.: Doctortown, 2 Sep 1904, Biltmore 1688m (US). Wheeler Co.: NE side of Little

Ocmulgee River NNE of Rae, 25 Feb 1973, Duncan 28914 (GA). Wilcox Co.: Near

Lake Wilco in SE corner of county, 17 May 1953, Hardin 16128 (GA). Worth Co.:

Banks of Flint River, 1.9 mi W of Warwick, 17 Aug 1966, Faircloth 3929 (GA). Kansas.

Anderson Co.: 2.5 mi W of Garnett, 18 May 1969, Magrath 3855 (GH). Barber Co.:

SW ¼ of T32S, R13W, 12 May 1973, Barrell 26-73 (US). Chautauqua Co.: Bluffs of

Middle Caney Creek, near Sedan, 21 Jul 1933, Palmer 41809 (A). Cherokee Co.: Near

Galena, 6 Jul 1924, Palmer 25339 (A). Cowley Co.: Arkansas City, 11 May 1922,

Palmer 21244 (A). Crawford Co.: Near Pittsburg, 20 Apr 1922, Palmer 20826 (A).

Montgomery Co.: T32S, R14E, Sec 15, 14 Oct 1956, Lathrop 3310 (GH). Wilson Co.:

Near Neodesha, 19 Sep 1922, Palmer 22030 (A). Louisiana. Acadia Parish: Fence row ca. 2 mi SE of Maxie, 17 Jun 1964, Thieret 17576 (FSU). Bienville Parish:

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Arcadia, 7 Jul 1965, Fulmer s.n. (LSU). Bossier Parish: E side of Red River, Sec 16, ca. 3 mi E of Hosston, 2 Oct 1965, Thieret21086 (FSU). Caddo Parish: E of US 71 N of

Mira and S of Ida, Sec 26, T23N, R15W,8 Jul 1994, Thomas & Price 140609 (TENN);

Kendrick Rd W of LA 1, ca. 2.7 mi N of Vivian, Sec 11, T22N, R16W, 1 Jun 1984,

Thomas 89025 (USF). Calcasieu Parish: NNE of Moss Bluff on property of Camp

Wee-Ta-Wenton, N side of Calcasieu River, ca. 2 air mi W of US 171 and W of small stream running N-S to Goldsmith Canal, T9S, R8W, S2, 7 Nov 1997, Mayfield 2664

(LSU); Shores of Lake Charles, 19 May 1915, Palmer 7699 (A). Caldwell Parish: 7.4 mi SE of jct US 165 and LA 849, S of Columbia, T12N, R4E, near jct of Secs 11, 12, 13,

14, 17 Aug 1989, Lievens 5876 (LSU); Copenhagen Hills, ca. 6 mi SE of Columbia, W side of Ouachita River, T12N, R4W, SE ¼, Sec 11 and NE ¼, Sec 14, 18 Oct 1988,

Urbatsch 5180.5 (LSU). Cameron Parish: 8 mi E of Cameron on LA 82, 19 Sep 1984,

Givens 4052 (LSU); Cameron, 7 Jul 1903, Tracy 8736 (A, US). Desoto Parish: Dickson

Prairie, ca. 2 air mi NW of Stonewall, NW ¼, S9, T15N, R14W, 24 May 2007, Reid 6142

(LSU). Evangeline Parish: Chicot State Park, 29 Apr 1960, Ewan 19968 (GA, GH).

Grant Parish: Roadside park along Hwy 71, 1 mi N of Hwy 8, E of Colfax, 28 Apr 1978,

Montz 4555 (LSU). Iberia Parish Avery Island salt dome, 11 Apr 1983, Givens 2949

(LSU). Jackson Parish: 4 mi S of Ruston, 15 Jul 1949, Moore s.n. (LSU). LaSalle

Parish: Standard, 1 Sep 1927, Whitehead s.n. (LSU). Lincoln Parish: 3 mi W of

Ruston, S21, T18N, R3W, 29 Jun 1955, Moore 6195 (USF). Natchitoches Parish: 5 mi

E of Creston, Sec 4, T11N, R6W, 26 Jul 1938, Brown 7154 (LSU); beside gov’t rd

(Natch. 104), 6.4 mi W of LA 9 and 4.1 mi E of Ashland and LA 115, Sec 12, T13N,

R7W, 28 Jul 1989, Thomas & Bell 111564 (TENN). Orleans Parish: New Orleans,

155

1832, T. Drummond 207 (GH #00075492–internet image!, SYNTYPE of Bumelia tomentosa); Little Oak Island, northernmost Indian midden in island chain, 21 Jul 1981,

McCook 900 (MISS). Ouachita Parish: NW of Frost Town and LA 151, Sec 6, T18N,

R1E, 5 Jul 1972, Thomas 30742 (TENN). Sabine Parish: Anthony’s Ferry crossing, 30

Jun 1973, Suttkus s.n. (GA). St. Landry Parish: 1.1 mi S of Opelousas on Lewisburg

Hwy, on E side of Southern Pacific RR, 22 Feb 1973,Lanclos 13 (LSU). St. Mary

Parish: W end of Bell Isle, 12 mi S of Calumet, ca. 15 mi S of Morgan City, 16 May

1959, Reese 2174 (GH). Cote Blanche Island, 13 Jul 1963, Thieret 16139 (FSU). St.

Tammany Parish: Ca. 3 mi SW of Isabel, T4S, R12E, S42, 5 Mar 1988, Smith 2566

(LSU). Tangipohoa Parish: Along the Tangipohoa River, 13 Mar 1976,Ghazali s.n.

(LSU). Union Parish: Cemetery off LA 15, Sec. 29, R1E, T20N, 11 Sep 1974, Smith

1747 (AUA). Vermilion Parish: Paul C. Rainey Refuge, Chenier Au Tigre, 15 May

1984, McKenzie s.n. (LSU). Vernon Parish: Bayou Zourie, 16 Aug 1991, Allen

PLK0698 (OKL); 0.2 mi W of Hwy 39 on Hwy 138, N of Leesville, 3 Oct 1936, Brown

6869 (LSU). Washington Parish: Along Pushepetappa Creek near Varnado, 5 Aug

1943, Brown 9768 (LSU). Webster Parish: Knottingham Cemetery, Camp Minden, 18

Jun 2002, Douglas 274 58m (LSU). West Feliciana Parish: River Bend Nuclear Power

Station, between US Hwy 61 and the Mississippi River near Star Hill, Apr 1985,

Urbatsch 4175 (LSU). Winn Parish: Kieffer Prairie, along walking trail E of 535, 0.75 mi

S of jct LA 156 and Gum Springs Rd (F.S. 535), 27 May 1987, Urbatsch 4453 (LSU).

Mississippi. Hancock Co.: Bay Saint-Louis, near the coast, 10 Aug 1952, Demaree

32697 (GH, MISS). Harrison Co.: Deer Island, W end, 29 Aug 1977, Brooks &

McDaniel 428 (FSU). Jackson Co.: 3 mi E of Ocean Springs, 2 Jan 1942, Duncan 4486

156

(GA). Lauderdale Co.: Meridian, 18 Apr 1922, Harbison 6042 (A). Marion Co.: Edge of swamp at Old Oxbow Lake, along Pearl River at Columbia, Hwy 98, 15 Jun 1966, Jones

6501 (MISS). Wilkinson Co.: 5.5 air mi NNW of Woodville, Smith Place, 22 Jul 1970,

Jones 19778 (MISS). Missouri. Barry Co.: Without location data, 16 Aug 1895,

Blankenship s.n. (GH). Benton Co.: Along Cole Camp Creek, 29 May 1896, Demetrio

47 (GH); bluffs of Osage River, near Warsaw, 24 June 1930, Palmer 36769 (A). Boone

Co.: E of rd to Claysville, 0.5 mi from Hwy 63, 30 Sep 1933, Jeffrey 351 (TENN).

Christian Co.: On lime glades tributary to Swan Creek, 4 mi SE of Chadwick, 6 Jul

1937, Steyermark 22991 (TENN). Cole Co.: Creek banks near Jefferson City, 3 May

1931, Palmer 39231 (A). Cooper Co.: Without location data, 11 Jun 1934, Bush 13654

(A). Crawford Co.: Meramec, 28 Jul 1886, Eggert s.n. (US). Dade Co.: Near Turnback,

5 May 1929, Palmer 35595 (A). Dunklin Co.: Near White Oak, 24 Apr 1931, Palmer

39047 (A). Franklin Co.: Gray Summit, 19 Sep 1938, Rehder 8507 (US). Greene Co.:

Along rocky stream near Springfield, 19 May 1926, Palmer 30148 (A). Hickory Co.:

Bluffs of Pomme de Terre River, near Hermitage, 22 May 1929, Palmer 35983 (A). Iron

Co.: Near Ironton, 17 May 1923, Palmer 22642 (A). Jasper Co.: Webb City, 4 July

1918, Palmer 14291 (A); Near Carterville, 13 Jul 1920, Palmer 18319 (A). Jefferson

Co.: 6.5 mi W of DeSoto, T39N, R3E, Sec 11, 38°07;30”N, 90°40’30”W, 9 Jul 1988,

Raven 27643 (GA). Lawrence Co.: Bluffs of Red Oak Creek, near Red Oak, 1 May

1925, Palmer 26980 (A). Madison Co.: Near Fredericktown, 7 Sep 1926, Palmer 31622

(A). Maries Co.: Lane’s Prairie, 8 May 1934, Bush 13470 (A). McDonald Co.: Without location data, 24 Jul 1893, Bush 236 (GH); Noel, 7 Aug 1908, Bush 4978 (US). Miller

Co.: Near Tuscumbia, 2 May 1931, Palmer 39220 (A). Morgan Co.: Without location

157

data, 11 Jun 1934, Bush 13691 (A). Osage Co.: 2 mi W of Westphalia on Maries River,

14 Jul 1933, Jeffrey s.n. (A). Ozark Co.: Hillsides along creek, near Bakersfield, 6 Oct

1927, Palmer 32819 (A). Pettis Co.: Without location data, 29 May 1934, Bush 13628

(A). Phelps Co.: Slaughter Sink, near Arlington, 9 July 1933, Palmer & Steyermark

41399 (A). Pulaski Co.: Ft Leonard Wood Army Base, ridge across Big Piney River from, and N of, gravel pit and Training Area 70, Sec 29, T35N, R10W, 15 Sep 1989,

Ovrebo W1075 (OKL). Ripley Co.: Bay Hills (?), 22 Jul 1897, Mackenzie 392 (US).

Shannon Co.: Rocky hillside near Montier, 7 Oct 1920, Palmer 19390 (A). St. Clair

Co.: Bluffs of Osage River near Osceola, 6 May 1929, Palmer 35646 (A). St. Francois

Co.: Bismarck, 25 Jun 1920, Palmer 18055 (A). St. Louis Co.: Without location data,

26 Jul 1887, Eggert s.n. (A). Stone Co.: Near Galena, 3 Jun 1914, Palmer 5862 (A,

US). Washington Co.: Near Irondale, 18 May 1926, Palmer 30172 (A). Wayne Co.:

Williamsville, 27 Jun 1914, Palmer 6113 (US). Webster Co.: Limestone glades near

Niangua, 8 Jun 1931, Palmer 39504 (A). Oklahoma. Adair Co.: Illinois River Valley, 2 mi N of Watts on US 59. 29 Sep 1959, Wallis 8401 (OKL). Atoka Co.: 7 mi W of Atoka,

19 May 1944, Hopkins & Nelson 340 (OKL). Beckham Co.: S of Prentiss, T9N, R24W,

SE ¼, SE ¼ Sec 7, 29 May 1992, Hoagland 092-007 (OKL); ca. 2.5 mi N and 5.5 mi E of Erick, T9N, R25W, Sec 13, 8 Jun 2000, Hoagland 393-00 (OKL). Blaine Co.:

Canton, 15 Aug 1915, Andrews 20 (A); Roman Nose State Park, 8 mi N of Watonga, 28

Oct 1980, Little 36330 (OKL). Bryan Co.: 2 mi W, 1.5 mi N of Matey, Sec 6, T5S, R12E,

20 Oct 1961, Taylor 587 (OKL). Caddo Co.: Devils Canyon, Hinton, 4 Oct 1964,

Sanders s.n. (OKL). Carter Co.: Arbuckle Mts, 27 Apr 1940, Hopkins 4705 (OKL);

Ardmore, 8 Jul 1916, Palmer 10396 (A). Cherokee Co.: 8 mi N of Talequah, 7 May

158

1938, Hopkins 3140 (OKL). Choctaw Co.: Ca. 6 mi E and 2 mi N of Hugo, on N Rd

4285 at Kiamichi Park, T6S, R18E, Sec 16, 19 Jun 2001, Hoagland & Buthod

HUGO461 (OKL). Coal Co.: 0.5 mi E of Coalgate Res, SNE/4, 11, T1N, R10E, 10 Jun

1998, Benesh et al. E148 (OKL). Comanche Co.: 20 ft S of Comanche Reformed

Church, Lawton, 1 Jul 1977, Akers 13 (TENN); Wichita National Forest, 10 Oct 1936,

Eskew 1418 (OKL). Cotton Co.: Randlett, 3 mi S and 3 mi E on section line rds from jct

Hwy 70 and Hwy 277/281, T5S, R12W12, Sec 13, 17 May 2000, Hoagland & McCarty

BLM0133 (OKL). Craig Co.: Along, Crow Creek, 1.5 mi S of Bluejacket, T27N, R21E,

Sec 32, 9 Jun 1999, Hoagland & Gray 0410-98 (OKL). Creek Co.: Stroud Lake, T15N,

R7E, Sec 6, 2 Nov 2000, Hoagland et al ab-134 (OKL). Custer Co.: E of Thomas, hills

SW of South Canadian River, 2 July 1977, Siegler 10690 (OKL). Delaware Co.:

Floodplain of Spavinaw Creek, near Jay, 8 May 1938, Hopkins 3348 (OKL). Ellis Co.:

Ca. 17 mi SW of Arnett along small stream that flows into the Canadian River from the

N, 12 Aug 1973, Taylor 14319 (OKL). Garfield Co.: 4 mi W and 7 mi N of Enid, near

Hellums Lake, 8 Oct 1932, Shirley 1050 (OKL). Grady Co.: 1.4 mi E of Cox City, 1 Sep

1963, Pearce 1049 (OKL). Greer Co.: Quartz Mtn State Park, 6 May 1980, Little 36059

(OKL). Harmon Co.: Ca. 2.5 mi S of Madge, at the crossing of the Salt Fork of the Red

River, T5N, R26W, Sec 31, 19 Jul 2000, Buthod et al. AB-3377 (OKL). Haskell Co.:

S18, T7N, R20E, 5 May 1998, Benesh et al. e058 (OKL). Hughes Co.: Holdenville

Lake, T7N, R9E, Sec 33, 19 May 1999, McCarty & Johnson m9.106 (OKL). Jackson

Co.: Altus Air Force Base, NW corner of base, UTM 04366, 38249, T3N, R20W, Sec

36, 10 Aug 1994, Johnson ALT0072 (OKL). Johnston Co.: 3.9 mi N of Coleman on

Hwy 48, 27 Jun 1698, Johnson 389 (OKL). Kay Co.: 1.4 mi E of Kaw City on Hwy 11 at

159

Sarge Creek Cove, T27N, R5E, Sec31, 8 Aug 2002, Buthod & Hoagland AB-2539

(OKL). Kingfisher Co.: 12 mi E and 6 mi S of Dover, Sec 12, T16N, R5W, 22 Jul 1982,

Johnson s.n. (OKL). Kiowa Co.: Along Mountain Creek W of Mountain View on Hwy 9,

T7N, R15W, Sec 12, 1 Nov 1997, Hoagland et al. 97-431 (OKL). Latimer Co.: Se corner of NW ¼ of Sec 19, T and R 351, 9 Jul 1976, Sanders 397 (OKL). LeFlore Co.:

10 mi S, 4.5 mi W of jct Hwys 59/270 and 128 in Heavener, Ouachita National Forest,

Indian Nations National Scenic and Wildlife Area, T03N, R25E, Sec 16 NE ¼,

34°44’19”N, 94°40’54”W, 6 Sep 1999, Morse 3945 (OKL). Logan Co.:From sh74c and

77 go S 0.7 mi, T12N, R2W2, S29, 5 Aug 1999, Hoagland 99-151 (OKL). Love Co.:

Floodplain of Red River, 4 mi S of Thackerville, 22 May 1938, Hopkins 3451 (OKL).

Major Co.: Near Cleo, 19 July 1913, Stevens 1720 (OKL). Marshall Co.: In Red River sand near a bay of Lake Texoma, 1.2 mi S of Enos and 2.5 mi E on unpaved rd, 17 Jun

1962, Hall 62617-25 (OKL); on campus (Univ. of OK?) just S of main building, 11 Jul

1975, Haxton 74 (OKL). Mayes Co.: Salina, on a bay of Lake Hudson, S side of Hwy 20

T21N, R20E, Sec 26, 9 Jun 1999, Hoagland & Gray 0360-98 (OKL). McClain Co.:

Johnson’s Pasture, 5 mi W of I-35 on Hwy 9, S of hwy, 15 Jul 1978, Milby 393 (OKL).

McCurtain Co.: 5 mi S of Bethel, 16 Oct 1937, Hopkins & Cross 2543 (OKL); Mt. Fork

River, Beavers Bend State Park, 10 mi N of Broken Bow, 31 Oct 1981, Little 37173

(OKL). McIntosh Co.: Raiford, 3.5 mi W on Hwy 9 and 8 mi N on section line rd, T10N,

R13E, Sec 12, 21 Apr 1999, McCarty & Johnson m9.057 (OKL). Murray Co.: 2 mi S of

Turner’s Falls, Arbuckle Mtns, 9 May 1940, Hopkins 4794 (OKL). Muskogee Co.: Camp

Gruber, E of Greenleaf Lake, Training Area 104, 15 Oct 1992, Johnson et al. GRU0248

(OKL); 1.5 mi S of Fort Gibson, 13 Sep 1959, Wallis 8311 (OKL). Noble Co.: Lake

160

McNurry Park, S25, T20N, R1E, 24 Sep 1997, Johnson nob08 (OKL). Okfuskee Co.:

Sec 21, T10N, R12E, Canadian River, 0.5 mi W of Hwy 84 on first section line rd N of river, 26 Apr 1997, Hoagland et al. 0224-97 (OKL). Oklahoma Co.: Oklahoma City at

Forest Park, T12N, R3W, Sec 13, 27 Apr 2004, Buthod et al. AB-4638 (OKL); along

Canadian River, Oklahoma City, 28 Sep 1922, Palmer 22107 (A). Okmulgee Co.: 0.5 mi E of Henryetta, S8, T11N, R13E, Vanderpool 739 (OKL). Osage Co.: Osage Hills

State Park, 10 mi NE of Pawhuska, 25 Apr 1982, Little 37321 (OKL). Ottawa Co.: 7.2 mi NE of Grove, at the Cherokee Boy Scout Camp, T26N, R23 EE, Sec 33, 17 Jul 2003,

Buthod & Hoagland AB-4136 (OKL); Lost Creek, 1 mi E of Wyandotte on State Rd 10, 4

Jul 1963, Wallis 8777 (OKL). Pawnee Co.: 3 mi E of Terlton, S29, T20N, R8E, 24 Sep

1997, Johnson paw06 (OKL). Payne Co.: 6 mi W of Stillwater, 13 Jul 1965, Hodges 83

(USF). Pittsburg Co.: 7 mi N of McAlester on Hwy 69, 17 May 7?, Siegler & Saupe

10336 (OKL). Pontotoc Co.: Pontotoc Ridge Preserve, Sec 31, T1N, R7E, 18 Jul 1997,

Folley PON0321 (OKL). Pottawatomie Co.: Sec 32, T8N, R5E, 0.6 mi S on 59 from jct with 9A at Maud, 22 Apr 1997, Hoagland 0102-97 (OKL). Pushmataha Co.: 4 mi E of

Albion, 9 May 1937, Hopkins & Cross 1798 (OKL). Rogers Co.: Blue Creek Boat Ramp at Oologah Lake, T23N, R16E, S22, 11 Sep 1997, McCarty 97045 (OKL). R. Mills Co.:

Washita Battlefield National Historic Site, T13N, R24W, Sec 12, 23 Jul 2002, Hoagland

WAS-046 (OKL). Seminole Co.: Sportsman Lake, S34, T9N, R7E, 9 Jul 1998, Benesh et al. E251 (OKL). Sequoyah Co.: Near Dwight Mission, 6 mi NE of Sallisaw, 12 Oct

1958, Wallis 7991 (OKL). Stephens Co.: Sec 2, T2S, R4W, 7 mi due N of the Hwy 89 and 53 jct, 15 Apr 1997, Hoagland & McCarty 0014-97 (OKL). Tillman Co.: Tipton, 6.5 mi E on Hwy 5C, from jct with Hwy 5, then 4.5 mi N on section line rds, T1N, R17W,

161

Sec 8, 4 Jun 1999, McCarty et al. m9.127 (OKL). Tulsa Co.: 1.5 mi W of Jenks, 18 Oct

1942, Willis 19 (OKL). Wagoner Co.: Chouteau WMA, UTM 39752, 02806, 2 Jul 1996,

Benesh et al. CH0110 (OKL). Washington Co.: T25N, R14E, S31, 3 Oct 1997,

McCarty 97143 (OKL). Washita Co.: 4 mi N of Dill City, on Hwy 42/NS Rd 216 at

Adams Lake, T10N, R18W, Sec 17, 14 Jun 2000, Hoagland & Buthod AB-1533 (OKL).

Woods Co.: SE corner of county, sandhills of the Cimarron River, 13 Jul 1972,

Nighswonger 1068, (OKL); ca. 8 mi SW of Waynoka, 16 Oct 1980, Nighswonger 1806

(OKL). Woodward Co.: Boiling Springs State Park, 6 mi E of Woodward, 7 Nov 1980,

Little 36485 (OKL). Texas. Archer Co.: Diversion Lake, 12 May 1935, Cory 13227 (A).

Austin Co.: 3 mi SW of Bellville on Mill Creek Rd, 25 Jun 1972, Whatley 53 (AUA).

Bowie Co.: Near Texarkana, 14 Sep 1898, Heller 4242 (A). Brown Co.: Limestone hills near Brownwood, 2 Nov 1925, Palmer 29567 (A). Chambers Co.: Hwy 565, ca. 0.5 mi

S of jct with Rd 1409, 22 Aug 1961, Traverse 2578 (A). Erath Co.: Hensailing Rd, 20

Jun 1956, Hoisington 350 (OKL). Galveston Co.: Banks of Dickinson Bayou tributary between Pine Lane and Oak Lane, crossing on Avenue L, S of Dickinson Bayou, extreme N side of Alta Loma, 8 Oct 1974, Waller 3227 (GH). Grayson Co.: S. of

Sherman, 9 Apr 1917, Slavin 356 (A). Harris Co.: Houston, 21 Nov 1915, Fisher 1819

(US); Houston, 7 May 1930, Fisher 63 (US). Harrison Co.: Marshall, 30 Mar 1918,

Palmer 13226 (US). Houston Co.: 5 mi NE of Weches, 12 Oct 1937, Cory 26113 (A).

Jefferson Co.: Beaumont, 16 Mar 1918, Palmer 13085 (A). Kaufman Co.: I-20 E of

Terrell at jct with TX Hwy 2728, 25 Apr 1998, Stewart 6238 (MISS). Knox Co.: Gypsum badlands 5 mi E of Benjamin, 6 Sep 1961, Correll & Johnston 54163 (GH). Llano Co.:

Sandy banks of Llano River, Llano, 24 Jun 1916, Palmer 10288 (US). Newton Co.:

162

Cow Creek, 8 Jun 1947, Nogle E7 (GH). Polk Co.: Livingston, 15 Apr 1914, Palmer

5262 (A). San Augustine Co.: San Augustine, without date, Crocket s.n. (US); limestone hills, San Augustine, 5 Jun 1915, Palmer 7892 (A). Upshur Co.: 8.5 mi NE of

Gilmer, 8 Oct 1937, Cory 25744 (GH). Wichita Co.: E of Wichita Falls, 10 Apr 1917,

Slavin 380 (A). Walker Co.: Huntsville, 26 May 1917, Palmer 12041 (A).

Sideroxylon lanuginosum Michx. subsp. rigidum (A. Gray) T.D. Penn., Fl. Neotrop. Monogr. 52:169. 1990. Bumelia lanuginosa (Michx.) Pers. var. rigida A. Gray, Syn. Fl. N. Amer. ed. 2, 2(1):68. 1886. Bumelia rigida (A. Gray) Small, Bull. New York Bot. Gard. 1:444. 1900. Bumelia lanuginosa (Michx.) Pers. subsp. rigida (A. Gray) Cronquist, J. Arnold Arbor. 26:453. 1945. TYPE: USA. TEXAS. UVALDE CO.: Uvalde, Sep 1879, E. Palmer 156 [LECTOTYPE: GH #00075476– internet image!; ISOLECTOTYPE: US #16120–internet image! Lectotypified by Pennington (1990, p. 169)].

Bumelia monticola Buckley, Bull. Torrey Bot. Club 10:91. 1883. TYPE: USA. TEXAS. EL PASO CO.: Mountains of El Paso Co., NW Texas, 1875, S.B. Buckley s.n. (HOLOTYPE: NY #00273377–internet image!).

Bumelia texana Buckley, Bull. Torrey Bot. Club 10:90. 1883. TYPE: USA. TEXAS. PECOS CO.: Mountains near the lower crossing of the Pecos River, Western Texas, 1875, S.B. Buckley s.n. (HOLOTYPE: NY #00273383–internet image!).

Bumelia pauciflora Engelm. ex A. Gray, Syn. Fl. N. Amer. ed. 2, 2(1):68. 1886. TYPE: USA. ARIZONA: By streams of Santa Catalina Mts., 16 Jun 1881, C.G. Pringle s.n. (HOLOTYPE: GH #00075489–internet image!; ISOTYPES: F #89401– internet image!; US #00955961–internet image!; VT–internet image!).

Bumelia riograndis Lundell, Contr. Univ. Michigan Herb. 8:77. 1942. TYPE: USA. TEXAS. JIM HOGG CO.: Between Hebbronville and Rio Grande City, Jul 1928, B.C. Tharpe s.n. (HOLOTYPE: MICH #1104628–internet image!).

Shrub or small tree, seldom over 8 m tall. Indumentum light brown to grey-white, the trichomes curled and ascending. Young twigs moderately shaggy-strigose to nearly glabrous, the T-shaped trichomes light brown to grey-white, thorns usually present at nodes. Mature twigs glabrous, deep longitudinal fissures appearing with age, the fissures exposing orange-red color of deeper bark, internode length 12–20 mm. Leaves

163

with petioles 2–12 mm long, petioles densely to sparsely shaggy-strigose to glabrous, the trichomes light brown to grey; leaf blades 1.4–5 cm long, 0.8–2.4 cm wide, oblanceolate to broadly obovate, the apex rounded to retuse, the base narrowly to broadly cuneate; secondary venation strongly brochidodromous, the major secondaries branching off midvein in 4–6 irregularly spaced pairs; adaxial surface dull, glabrous, the vein reticulum conspicuous; abaxial surface with indumentum varying from moderately densely, evenly, and persistently wooly-pubescent to glabrate, the T-shaped trichomes light brown to grey-white, the stalk 0.1–0.2 mm long, the upper portion 0.9–1.6 mm long, the upper portions mostly bent and curled, ascending, most veins evident, raised.

Pedicels 2–7 mm long, with indumentum varying from moderately densely and persistently shaggy-strigose to glabrate, the trichomes light brown to grey-white. Outer sepals 1.5–2.1 mm long, 1.8–2.5 mm wide, the inner sepals 1.5–2.3 mm long, 2.2–2.5 mm wide, suborbicular to reniform, all sepals densely and persistently short-strigose to glabrate, the trichomes light brown to grey-white. Corolla tube 1.2–1.6 mm long.

Staminodes deltoid to ovate, the base not reflexed. Ovary densely strigose, or glabrous proximally and densely strigose only on distal half.

Distribution and habitat. Southwestern Oklahoma, central and western Texas, southern parts of New Mexico and Arizona, northern tier of states in Mexico (Fig. 5-19).

Dry, rocky uplands and along mountain streams, elevation 450–2000 m.

Specimens examined. USA. Arizona. Cochise Co.: Beginning of Guadalupe

Canyon, 25 mi E of Douglas, 8 May 1974, Hess & Tyznik 3260 (OKL); Chiricahua Mtns,

1929, McKelvey 605 (A); Guadalupe Canyon, 8 mi E of Douglas, 26 May 1935, Peebles

11698 (US). Pima Co.: Bear Creek, Tucson, 26 Mar 1919, Eastwood 8164 (A).

164

Oklahoma. Comanche Co.: Medicine Creek, Mt. Scott, 10 May 1904, J.H. Gant(?) 163

(US). New Mexico. Grant Co.: Dog Spring, Dog Mtns, 19 Sep 1893, Mearns 2356

(US). Hidalgo Co.: 35 mi E from Douglas, AZ, in canyon that runs SW to NE from

Mexico to SE AZ and SW to NM, 24 Apr 1975, Hess & Stickney 3432 (OKL). Texas.

Bandera Co.: Roadside of TX 16, 1.4 mi W of Bexar-Bandera Co. line, 28 Jun 1984,

Lievens s.n. (LSU). Bell Co.: Banks of Leon River, W of old Tennessee Valley site, 8

May 1954, York 54300 (OKL). Bexar Co.: Along Cibolo Creek, Leon Springs Military

Reservation, 10 Aug 1956, Cappel T328 (FSU); near intersection of Babcock Rd and

Heuermann Rd in NW part of the county, 15 Jul 1984, Lievens s.n. (LSU). Blanco Co.:

Jul 1885, Reverchon 1555 (A). Borden Co.: Dorwood’s ranch, 19 Jun 1904, Coville

1889 (US). Bosque Co.: Edwards Plateau, S of Walnut Springs, 3 Jul 1953, Manning

53037 (FLAS). Brewster Co.: Dog Gap, Santiago Mtns., 14 Apr 1936, Cory s.n. (A).

Brown Co.: Brownwood, 5 Jul 1916, Palmer 10378 (A). Burnet Co.: At Granite

Mountain near roadside picnic area along Ranch Rd 1431, 1.9 rd mi W of jct of Ranch

Rd 1431 and US 281, just W of Marble Falls, 24 Jun 1991, Lievens 4933 (LSU); near

Granite Mountain, 22 Jun 1916, Palmer 10270 (FSU). Callahan Co.: 8 Jul 1941, Tharp

42-35 (GH). Cameron Co.: Loma Alto, 8 air mi NE of Brownsville, 30 Nov 1945, Cory

51394 (GH). Coke Co.: Bronte, 1 Jul 1916, Palmer 10355 (A, US). Coleman Co.: Dry limestone hills, Santa Anna, 6 Jul 1916, Palmer 10386 (A). Collingsworth Co.: Along

Hwy 203, along Salt Fork of Red River, 9 mi E of Willington, 22 Apr 1972, Taylor 10148

(OKL). Comal Co.: Fischer’s Store, 7 Jun 1917, Palmer 12208a (A). Concho Co.: 2 mi

NW of Paint Rock, 7 Sep 1934, Cory 9761 (A). Coryell Co.: 7 mi E of Evant, 20 Aug

1973, Godfrey 72388 (FSU). Crockett Co.: 19 Apr 1929, Cory 602 (GH). Dallas Co.:

165

Dallas, 26 Jun 1901, Reverchon 2565 (GH). Duval Co.: San Diego, Apr 1882, Buckley s.n. (A). Edwards Co.: 10.75 mi SE of Rocksprings, 14 Aug 1937, Cory 23798 (A).

Erath Co.: Stephenville, 21 Jun 1918, Palmer 14176 (A). Freestone Co.: 15 mi S of

Fairfield, 18 Jul 1953, Shinners 15340 (GA). Gillespie Co.: Bear Mountain, 9 May

1935, Cory 12925 (A). Fredericksburg, 5 Jun 1916, Palmer 10057 (A). Hamilton Co.:

Prairie ravine, 8 mi S and 3 mi W of Hamilton, 13 May 1967, Stanford 1079 (USF).

Howard Co.: Big Spring, 23 Oct 1917, Palmer 13066 (A). Irion Co.: Banks of streams,

Mertzon, 4 Jul 1917, Palmer 12426 (A). Jim Hogg Co.: Hebbronville–Rio Grande City,

17 Jul 1928, Tharp 6009 (US). Jones Co.: 9 mi SE of Anson, 24 Sep 1935, Cory 15807

(A). Kendall Co.: Along rocky creeks, Boerne, 18 May 1918, Palmer 13648 (A). Kerr

Co.: Kerrville, Jul 1909, Mackensen 5 (A); Rocky bluffs of Guadalupe River, Kerrville, 9

Jun 1917, Palmer 12210 (A). Kimble Co.: Rocky ground along river, Junction, 6 Oct

1916, Palmer 10913 (A). Llano Co.: House Mt., 30 Jun 1892, Nealley 82 (US). Menard

Co.: High ledges, Menard, 12 May 1917, Palmer 11894 (A). Mitchell Co.: Colorado, 28

May 1918, Palmer 13787 (A). Nolan Co.: Sweetwater, 6 Jul 1917, Palmer 12431 (A); ibid., 28 Sep 1918, Palmer 14522 (A). Palo Pinto Co.: Strawn, 26 Jun 1918, Palmer

14246 (A). Pecos Co.: Just SW of Sheffield, on and below rimrock of mesa, 21 Jun

1963, Correll & Wasshausen 27975 (FSU). Real Co.: Barksdale, 7 May 1918, Palmer

13525 (A). San Saba Co.: San Saba, 5 May 1917, Palmer 11810 (A). Schleicher Co.:

11.75 mi N of Eldorado, along draws which drain into the S. Concho River, 7 Oct 1946,

Cory 52506 (GH). Scurry Co.: Camp Springs, 11 Jul 1963, Correll & Ogden 28456

(GH). Sutton Co.: NNE of Sonora, Clark & Cory 550 (GH); Sonora, 22 Aug 1940, Reed

3 (LSU). Taylor Co.: Abilene, 18 May 1900, Williams s.n. (US). Terrell Co.: Near

166

Sanderson, 24 Apr 1928, Palmer 33442 (A). Tom Green Co.: Banks of Concho River,

San Angelo, 28 Jun 1916, Palmer 10322 (A). Travis Co.: Near Austin, 27 May 1904,

Coville 1822 (US). Uvalde Co.: Frio River, Con Can, 13 Apr 1917, Palmer 11545 (A).

Val Verde Co.: Without data, 12 Jul 1941, Tharp 42-34 (OKL). Webb Co.: Between

Laredo Country Club Golf Course and Del Mar, ca. 0.25 mi E of McPherson,5 Aug

1993, Lillie 183 (LSU). Mexico. Chihuahua: La Morita, 60 mi W of Casas Grandes, 11

Oct 1939, Muller 3716 (GH). Coahuila: Sierra de San Antonio, canyon at San Antonio de los Alamos, 2–3 Sep 1940, Johnston & Muller 913 (USF). Sierra de Hechiceros:

Canyon del Indio Felipe, near Chihuahuan boundary NE (beyond Puerto del Aire) from

Rancho El Tule, 18 Sep 1940, Johnston & Muller 1354 (GH); Sierra de Santa Rosa, S of Muzquiz, 27 Jul 1938, Marsh 1553 (GH). Parras, 111.5 mi W of Saltillo, 8 to 28 Jun

1880, Palmer 787 (US); Saltillo and vicinity, Jun 1898, Palmer 232 (GH); Villa Acuna,

Near Santo Domingo, 3 Jul 1936, Wynd & Mueller 463 (A). Nuevo Leon: Rancho

Resendez, Lampazos, 24 Jun 1937, Edwards 342 (GH); 8 mi E of Dulces Nombres, an just E of border into Tamaulipas, Sierra Madre Oriental, 25 Jun 1948, Meyer & Rogers

2665 (GH); Sierra Madre Mtns near Monterrey, 15 Jul 1933, Mueller 208 (A). Sonora:

Santa Rosa Canyon, near Bavispe, 15 Jul 1938, White 503 (GH). Tamaulipas: Vicinity of San Jose, 2 Jul 1930, Bartlett 10010 (GH, US).

Specimens intermediate between subsp. albicans and subsp. rigidum.

Specimens examined. USA. Texas. Coryell Co.: 7 mi E of Evant, 20 Aug 1973,

Godfrey 72388 (FSU); Erath Co.: Hensailing Rd, 20 Jun 1956, Hoisington 350 (OKL).

Dallas Co.: Turtle Creek and Stonebridge Drive, Dallas, 9 Oct 1948, Shinners 10579

(GA). Hamilton Co.: Prairie ravine, 8 mi S and 3 mi W of Hamilton, 13 May 1967,

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Stanford 1079 (USF). Hayes Co.: San Marcos, 1 Jun 1917, Palmer 12123 (A). Mexico.

Nuevo Leon: Mountain canyons near Monterey, 11 Jun 1888, Pringle 2100 (A). Sierra

Madre Oriental, limestone slopes of Chipinque Mesa, SW of Monterey, altitude ca. 3500 ft, 8 Jun 1962, Webster et al. 11225 (GH).

Specimens intermediate between subsp. albicans and subsp. lanuginosum.

Specimens examined. USA. Texas. Brazos Co.: 2 mi S of College Station, 17

Aug 1940, Taylor s.n. (US). Tarrant Co.: 2 Apr 1923, Ruth 202 (GH). Harris Co.: Along creek, Houston, 2 Apr 1917, Palmer 11456 (A). Somervell Co.: 2 m above Squaw

Creek, Glen Rose, 9 Oct 1891, Ward s.n. (US). Travis Co.: Ca. 5 mi S of Austin, 16

May 1940, Lundell 8920 (GH).

Specimens intermediate between subsp. rigidum and subsp. lanuginosum.

Specimens examined. USA. Texas. Brown Co.: Near Brownwood, 2 Nov

1925, Palmer 29567 (A). Burnet Co.: Burnet, 21 Jun 1916, Palmer 10257 (A).

Collingsworth Co.: 10 mi NE of Wellington, E side of Salt Fork of Red River, 13 Oct

1945, Cory 50163 (US). Crockett Co.: 1854, Bigelow s.n. (GH). Dallas Co.: Dallas, 26

Sep 1900, Bush 1107 (US). Edwards Co.: Northern part of county, 10 Oct 1916,

Palmer 10975 (A, GH). Hardeman Co.: 12 mi N of Chillicothe, 13 May 1935, Cory

13369 (A). Kendall Co.: Spanish Pass, 26 Aug 1936, Cory 19343 (A); Boerne, 1911,

Hastings s.n. (A); banks of Cebelo Creek, Boerne, 22 May 1916, Palmer 9840 (A). Kerr

Co.: Kerrville, 30 May 1916, Palmer 9937 (A); Lacey’s ranch, 10 Jun 1917, Palmer

12229a (A). Kinney Co.: 10.75 mi W of Laguna, West Fork of Nueces River, 24 Sep

1939, Cory 33465 (A). Llano Co.: Enchanted Rock, 19 Sep 1937, Cory 24588 (A).

Menard Co.: Rocky creek banks in canyon, Menard, 12 May 1917, Palmer 11899 (A).

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Palo Pinto Co.: Along streams, Strawn, 27 Jul 1918, Palmer 14266 (A). San Saba Co.:

San Saba, 8 May 1917, Palmer 11844 (A). Sutton Co.: Between Sonora and “Swayer

Spring” at head of Llano River, 16 Jul 1920, Eggleston 16729 (US). Uvalde Co.: Bluffs of Frio River, Coneau, 14 Jun 1916, Palmer 10203 (A, US). Val Verde Co.: In limestone canyon near Shumla, 25 Apr 1928, Palmer 33489 (US).

Discussion. Sideroxylon lanuginosum, along with S. reclinatum, named by

Michaux (1803), were the third and fourth North American species of Sideroxylon to be described. Of these North American species, S. lanuginosum is the most geographically widespread, ranging from Florida and Georgia in the east to Arizona and northern

Mexico in the west, and north as far as Missouri and Kansas (Fig. 5-19). The considerable morphological variation within this wide-ranging species has provided a rich opportunity for taxonomists to recognize segregate species, subspecies, and varieties based on characters such as leaf size, abaxial leaf indumentum, color of leaf trichomes, and thorn presence. Based on my own observations, along with those of

Clark (1942), Cronquist (1945), Pennington (1990), and Elisens et al. (2009), each of these morphological variants correlates with a particular geographical region. Among more recent authors, Clark (1942) recognized two varieties under Bumelia lanuginosa: var. albicans and var. oblongifolia, as well as three segregate species, Bumelia rigida,

B. rufa, and B. texana. Cronquist (1945) grouped the variants differently (Fig. 5-20), recognizing two subspecies under B. lanuginosa: subsp. oblongifolia and subsp. rigida, with each subspecies subdivided into varieties: subsp. oblongifolia var. oblongifolia and var. albicans, and subsp. rigida var. rigida and var. texana. Pennington (1990) transferred Bumelia to Sideroxylon, and generally followed Cronquist for species

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delimitations, but within Sideroxylon lanuginosum he recognized Cronquist’s subspecies without varieties: S. lanuginosum subsp. oblongifolium, and subsp. rigidum. Flora of

North America follows Pennington’s classification (Elisens et al. 2009), which was in wide use at the time.

Sideroxylon lanuginosum subsp. lanuginosum sensu Pennington (1990) represents the populations at the eastern end of the species distribution, from Florida and Georgia through Louisiana, i.e., east of the Mississippi River, diagnosed by the red- brown to brown color of its relatively dense and persistent abaxial leaf indumentum (Fig.

5-18). Sideroxylon lanuginosum subsp. oblongifolium sensu Pennington (1990) refers to populations west of the Mississippi, from Missouri and Kansas south through Arkansas,

Oklahoma, western Louisiana, and eastern and central Texas, diagnosed by the grey to white color of its generally relatively less dense and occasionally ephemeral abaxial leaf indumentum. While there is a tendency toward grey leaf trichomes as one proceeds westward from Alabama, my examination of specimens from west of the Mississippi reveals that grey-haired and brown-haired plants are broadly intermixed throughout the region, with many that could be called intermediates (Fig. 5-20). Thus I conclude that subsp. oblongifolium cannot be reliably distinguished from subsp. lanuginosum, and I here include it within an expanded subspecies lanuginosum.

Sideroxylon lanuginosum subsp. rigidum sensu Pennington (1990) represents populations at the western end of the species distribution, from southwestern Oklahoma through central and western Texas, extending sparingly into New Mexico and Arizona, and south into the northern tier of states in Mexico (Fig. 5-19). The range of this subspecies corresponds to xeric environments at higher elevations, i.e., above ca. 450

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m. The plants prefer rocky uplands and slopes near mountain streams, and they are generally thornier, and shorter in stature, than in the other two subspecies. Subspecies rigidum is diagnosed chiefly by its smaller leaf size (length 5 cm or less). Based on leaf size, there is a zone of intergradation in central Texas between subsp. rigidum and the other two subspecies: subsp. lanuginosum and subsp. albicans (Fig. 5-19). Since this zone of intergradation is quite narrow, I find it useful to recognize subsp. rigidum, and consider it as representing an eco-geographical race. Within subsp. rigidum there appear to be two variants. One variant, corresponding to Cronquist’s Bumelia lanuginosa subsp. rigida var. rigida and J.K. Small’s B. rigida, has more or less persistent abaxial leaf indumentum, and is found in central (but not western) Texas, south into northern Mexico, then north into southern New Mexico and Arizona (Fig. 5-

20). The other variant, corresponding to Buckley’s Bumelia texana and B. monticola, and Cronquist’s B. lanuginosa subsp. rigida var. texana, has glabrate leaves, and is found in central and southern Texas and Nuevo Leon, Mexico (Fig. 5-20). Among all of these small-leaved plants of rocky uplands near mountain streams, abaxial leaf indumentum is quite variable, and thus I find no basis for formally recognizing these two variants. They are here considered within subsp. rigidum, and merely represent extremes within the nearly continuous pattern of variation in abaxial leaf indumentum among these western populations.

Sideroxylon lanuginosum subsp. albicans represents populations inhabiting a fairly restricted range in southeastern and east central Texas, southward sparingly into northeastern Mexico (Fig. 5-19). The indumentum of the abaxial leaf surface is relatively longer-haired and more matted than in the other two subspecies, and it is bright white in

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color, which, according to Sargent, who named the taxon, “gives the tree such a different appearance from the common form that it can perhaps be well distinguished as

Bumelia lanuginosa var. albicans…” (1921, p. 168). I agree with Sargent–specimens of this variant are easily recognizable by their white trichomes, and also their typically longer pedicels. Around the edges of the range of subsp. albicans, intermediates can be found between this subspecies and subsp. lanuginosum and subsp. rigidum (Fig. 5-19).

According to specimen label data and the field observations of Clark (1942), subsp. albicans features the tallest trees of all the North American species of Sideroxylon, with heights reaching ca. 20 m. More often than not, this subspecies is found in sandy river bottomlands, but it also occurs in some drier upland environments. Scanning election microscope (SEM) study of the abaxial leaf micromorphology of the North American species of Sideroxylon shows that differences in stomatal complexes and other cuticular surface features can be taxonomically useful at the species level. With further study, the distinctive-looking subsp. albicans might be found to be worthy of recognition as a species, but it should be noted that SEM images (Fig. 5-17) reveal no striking differences in stomatal structures among the subspecies of Sideroxylon lanuginosum.

Therefore, at this time I consider recognition at subspecific rank to be most appropriate– a conclusion reinforced by the frequency of intermediate specimens on the periphery of its range.

Morphological phylogenetic analysis (Chapter 3) supports S. lanuginosum and its subspecies as a cladospecies that is sister to the S. reclinatum complex; all three entities share in common one character state that differs from all the other species in

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the section: the stalk of the T-shaped trichomes of the abaxial leaf indumentum is greater than 0.1 mm in length. In the other species it is less than 0.08 mm long.

Nomenclatural notes. The type specimen of Sideroxylon lanuginosum Michx. housed at Paris (P) is labeled “Isotype”, but it is the holotype.

Sideroxylon lanuginosum Michx. subsp. typica Cronquist (1945) is an illegitimate name, as “typical” names are not allowed by the Code (article 24.3). The name, of course, is equivalent to S. lanuginosum Michx. subsp. lanuginosum.

Chrysophyllum ludovicianum Raf. is listed by Clark (1942) as a synonym of

Bumelia lanuginosa (Michx.) Pers., but with a question mark. Clark’s hesitation may stem from Rafinesque’s protologue (1817), where he describes the abaxial leaf indumentum as sericeous (“…subtus sericeis…”), which is unlikely for Sideroxylon lanuginosum, whose indumentum is loosely wooly. Sideroxylon lanuginosum subsp. albicans can have leaf trichomes that are longer and more appressed, but the appearance is not quite sericeous. Subspecies albicans is not known from Louisiana, nor is Sideroxylon tenax, whose leaf indumentum is truly sericeous. I conclude that

Rafinesque was probably referring to a locally aberrant plant of S. lanuginosum, a species common in Louisiana, and used the term “sericeous” loosely. Therefore I have neotypified the name from among Louisiana specimens, and kept it in the synonymy of

Sideroxylon lanuginosum Michx.

The name Bumelia spinosa appeared in the synonymy of Sideroxylon lanuginosum subsp. rigidum (Pennington 1990, Govaerts et al. 2001). Pennington

(1990, p. 169) listed it as “Bumelia spinosa A. DC. sensu S. Watson”, and Govaerts et al. (2001, p. 299) listed it as “B. spinosa S. Watson”. Watson (1883) applied the name

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Bumelia spinosa A. DC. to specimens collected in Texas Arizona, and northern Mexico by Palmer (#156), Lemmon, and Pringle. DeCandolle’s description of B. spinosa (1844) refers to a shrub in Mexico with small, glabrous leaves and oblong fruit; Pennington

(1990) listed this name as a synonym of Sideroxylon celastrinum (Kunth) T.D. Penn., a plant which matches DeCandolle’s description, although Pennington placed a question mark next to the synonym. Gray (1886, p. 68), in his description of Bumelia lanuginosa var. rigida, used a question mark, listing “B. spinosa, Watson … not DC. ?”, referring to specimens from Texas collected by Wright and Palmer, and from Arizona by Pringle and Lemmon, clearly the same specimens mentioned by Watson (1883). Gray’s and

Pennington’s question marks perhaps stem from the fact that DeCandolle’s description could be interpreted to refer either to Sideroxylon celastrinum or to Mexican specimens of S. lanuginosum subsp. rigidum. Given this uncertainty, I believe Bumelia spinosa does not belong in the synonymy of Sideroxylon lanuginosum subsp. rigidum; therefore it is here excluded. The name cannot be precisely applied at this time.

Labeled as isotypes of Bumelia riograndis Lundell are collections by B.C. Tharpe

[USA. Texas. Starr Co.: Arroyo in gravelly hills near Rio Grande City, between Rio

Grande City and Hebbronville, Jul 1928, B.C. Tharpe 6009 (TEX, 2 sheets, #00372384,

#00372385–internet images!)]. Lundell (1942) clearly designated B.C. Tharp s.n.

(MICH) as the type, collected Jul 1928 in Jim Hogg Co., TX, between Hebbronville and

Rio Grande City. Although the two specimens at TEX are given the same date and general location as Lundell’s holotype, the county is different, and the specimens bear the collection number Tharpe 6009. Therefore, it is clear that these sheets are not part

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of the same collection as B.C. Tharp s.n. (at MICH), and I conclude that the TEX sheets should not be considered type material.

6. Sideroxylon reclinatum Michx., Fl. Bor. Amer. 1:122. 1803.

Shrub, single to many-stemmed, 0.5–3 m tall, occasionally a small tree to 4 or 5 m tall, trunk diameter 1-7 cm; Indumentum of unicellular, light brown to blonde to grey- white, rarely red-brown, T-shaped trichomes, symmetric or asymmetric, terete and hollow to flattened in cross-section, having a short stalk and a longer top portion of varying length, the top portion straight and appressed to curled and ascending.

Vegetative buds densely wooly-pubescent with short, curled, ascending, light brown to red-brown T-shaped trichomes, the stalk 0.02–0.07 mm, the top 0.2–0.7 mm. Young twigs (long shoots) 0.8–1 mm wide, terete, glabrous, or sparsely pubescent and quickly becoming glabrous, smooth, green to red-brown, prominently dotted with lenticels; thorns often present at nodes, especially on young stems, thorns 0.3–2 cm long, some becoming short spur shoots or lengthening to become side branches. Mature twigs glabrous, becoming longitudinally fissured and fading to grey-brown or light grey by second season, sometimes becoming mottled tan and grey, the surface remaining relatively smooth, or becoming rough and gnarled in subsequent seasons with transverse fissures appearing along with deepening longitudinal fissures, giving bark a somewhat rectangularly plated appearance, woody galls sometimes present on older twigs, leaves clustered on stumpy brachyblasts, internode length 7–33 mm. Leaves tardily deciduous, alternate and spirally arranged on young long shoots, becoming fascicled on brachyblasts on older stems, petioles canaliculate, 4–5 mm long on young long shoots, 2–7 (–10) mm long on short shoots, and glabrous, or young petioles having

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a sparse to moderately dense, deciduous to persistent indumentum, blonde to light brown, fading to grey-white if persistent; leaf blades on young long shoots 19–50 mm long, 12–21 mm wide, rhombic to elliptic to obovate, blades on short shoots 8–52 (–70) mm long, 4–26 (–37) mm wide, narrowly to broadly obovate, sometimes elliptic, coriaceous, the apex rounded, occasionally retuse or bluntly (rarely sharply) acute, the base acute to cuneate/decurrent, sometimes slightly concave, the margin entire, blades of mature leaves flat to markedly involute; venation pinnate and conspicuously finely reticulate, brochidodromous, with secondary veins slightly decurrent, branching off midvein in opposite to alternate arrangement, ± in 6–10 irregularly spaced pairs, with an intersecondary vein occasionally occurring between secondaries, the tertiary and quaternary veins irregular-reticulate, the quinternary veins irregular-reticulate to freely ramifying, areolation moderately developed, the marginal ultimate venation looped; adaxial surface dark green, semi-glossy, sparsely pubescent when young with fine trichomes, becoming glabrous, the vein reticulum conspicuous, the veins impressed

(fresh leaf) to raised (dried leaf), giving the surface a finely textured veiny appearance; abaxial surface glabrous, young leaves sometimes very sparsely pubescent with quickly deciduous, fine blonde to light brown trichomes and becoming glabrous, trichomes sometimes persistent only along midvein, or sparsely to densely covered with a more persistent, finely wooly indumentum, on young leaves light brown, sparse to moderately dense and matted, sometimes at least partially obscuring the leaf surface, on older leaves fading to grey-white and becoming less dense to glabrate, the trichomes T- shaped, terete and hollow or flattened in cross-section, with stalk 0.02–0.08 mm long, upper portion 0.3– 1.5 mm long, the upper portions straight and appressed to curled

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and ascending, veins flush to slightly raised (fresh leaf) to raised (dried leaf); stomata

(Figs. 5-21, 5-22) recessed inside dome-like, ellipsoidal chambers raised slightly from leaf surface, the chamber openings wide and elliptical, guard cells often visible through the opening, each opening surrounded by a more or less well-developed series of irregularly concentric cuticular ridges, often also with ridges radiating out perpendicular to the opening; cuticular features of low to strong relief, the surface between stomatal complexes smooth and irregularly undulating to elaborately ornamented with a reticulating pattern of grooves and ridges, epidermal cell boundaries obscure to evident, marked, if visible, by an impressed groove or by a raised ridge with or without an impressed groove along its middle. Inflorescence a fascicle borne in a leaf axil, fascicles often clustered on short spur shoots in axils of fallen leaves, each cluster having ca. 3–

30 pedicellate flowers, the pedicels 2–12 mm long, glabrous to densely to sparsely wooly-strigose at anthesis, often becoming glabrous in fruit. Calyx of 5 (–6) quincuncial, free sepals, the outer two sepals 1.3–2 mm long, 1.3–2 mm wide, ovate to suborbicular, the apex rounded, rarely acute, the margin entire, usually with thin zone of translucent tissue, the inner three sepals 1.2–2.2 mm long, 1.7–2.4 mm wide, suborbicular, the apex rounded to retuse, the margin entire to erose, with broad zone of thin translucent tissue, sepals glabrous to moderately densely pubescent with persistent indumentum of light brown to red-brown T-shaped trichomes, wooly on the outer, sericeous on the inner. Corolla white, cyathiform, sympetalous, the tube 1.3–1.8 mm long, enclosed within the calyx; the lobes 5, exserted and spreading, glabrous, each with a median lobe and two lateral segments, the lobes 5 (–6), exserted and spreading, glabrous, each with a median lobe and two lateral segments, the median lobe 1.5–2 mm long, orbicular,

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clawed, cupped around a stamen, the lateral segments 1.7–2.2 mm long (from junction with adjacent lateral segment), 1.2–1.8 mm long (from junction with median lobe), 0.7–1 mm wide, lanceolate, all corolla margins erose, translucent. Stamens 5, epipetalous, opposite the corolla lobes, exserted; 1.3–1.8 mm long, 0.2–0.4 mm wide, fixed at top of corolla tube, dilated proximally and narrowing toward anther attachment; anther 0.9–1.2 mm long, sagittate, ventrifixed at the point of the sinus, extrorse, opening by two dorsal longitudinal slits. Staminodes petaloid, alternating with stamens, each staminode 1.7–

2.2 mm long, 0.8–1.5 mm wide, reaching ca. 0.7 times–0.9 times the length of median corolla lobe, sometimes equaling or exceeding the median lobe, lanceolate to deltoid, infolded, base occasionally slightly reflex, margin erose, translucent. Ovary superior, 5–

(6 –) loculate, locules uniovulate with basal-axile placentation, ovary ca. 0.8–1.3 mm long, 0.7–1.1 mm wide, globose to ovoid, tapering abruptly to style, the ovary at anthesis glabrous, or with a few pale trichomes basally, or pubescent with moderately dense, sericeous indumentum of straight, appressed, white to light brown T-shaped trichomes, the trichomes longer on distal part of ovary; style 1–1.3 mm long, glabrous, included. Fruit a berry, one (rarely 2)-seeded, 6.3–11 mm long, 6–10 mm wide, ellipsoid to slightly obovoid to subglobose, black, glossy, glabrous. Seeds 4–7 mm long, 3.2–6 mm wide, subglobose to ellipsoid, the testa hard, smooth, glossy, the color dark to light brown, solid to boldly variegated; the hilum scar basal, usually bipartite, the larger part basal, ± half-moon shaped, 0.7–2.2 mm long, 1.0–2.8 mm wide, the smaller part abaxial to the other part, ± roughly V-shaped, 0.2–1.2 mm long, 0.8–2.8 mm wide, the parts well-separated by a bridge of testa, the scar being the exposed portion of a hollow

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cavity under the testa extending a small distance around the basal end of the seed, the cavity filled, especially on the abaxial side, with a yellowish fatty substance.

Distribution and habitat. Sideroxylon reclinatum is found throughout Florida, a few counties in southern Georgia, and it has been infrequently collected in Alabama and

Louisiana (Fig. 5-23). It is a plant of calcareous or sandy, wet to mesic wooded habitats.

Phenology. Flowering April–June, fruit ripening June–August.

Illustrations. Godfrey (1988, Fig. 320, by Melanie Darst); Ventenat (1803, Pl.

22).

Key to the Subspecies of Sideroxylon reclinatum

1. Young twigs and leaves glabrous, or sparsely pubescent with quickly deciduous, fine, blonde to light brown trichomes; mature leaves glabrous or with a few blonde to light brown trichomes persisting along midvein; sepals, pedicels and ovary glabrous or with very few pale trichomes; abaxial leaf epidermal cell outlines obscure, or if visible, defined by raised ridges that lack an impressed groove along their middle ------S. reclinatum subsp. reclinatum

1. Young twigs and leaves densely to sparsely pubescent with brown, finely wooly trichomes; mature leaves glabrous to densely pubescent across abaxial lamina with finely wooly, matted, brown to grey indumentum; sepals, pedicels, and ovary glabrous to densely pubescent with brown trichomes; abaxial epidermal cell outlines always clearly visible, strikingly defined by impressed grooves, or raised ridges with impressed grooves along their middle ------S. reclinatum subsp. austrofloridense

Sideroxylon reclinatum Michx. subsp. austrofloridense (Whetstone) Kartesz & Gandhi, Phytologia 68:425. 1990. Bumelia reclinata (Michx.) Vent. var. austrofloridensis Whetstone, Ann. Missouri Bot. Gard. 72:545. 1985. TYPE: U.S.A. Florida. Dade Co.: Everglades National Park, 7 July 1984, R.D. Whetstone 14459 (HOLOTYPE: JSU).

Shrub, single to many-stemmed, 0.5–3 m tall; rarely a small tree. Indumentum light brown to grey-white, rarely red-brown, the T-shaped trichomes terete and hollow to flattened in cross-section, the top portions curled and ascending. Young twigs red- brown, sparsely lanulose to glabrate, quickly becoming glabrous. Mature twigs glabrous,

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the smooth outer surface becoming longitudinally fissured and fading to light grey by second season, becoming rough and gnarled in subsequent seasons, transverse fissures appearing along with deepening longitudinal fissures, giving bark a somewhat rectangularly plated appearance, woody galls frequently present on older twigs. Petioles

2–5 mm long on short shoots, glabrous, or young petioles having a sparse to moderately dense, persistent indumentum, blonde to light brown, fading to grey-white with age; leaf blades on short shoots 8–52 mm long, 5 –19 mm wide, narrowly obovate, occasionally elliptic, often markedly involute; abaxial surface glabrous or often sparsely to densely covered with a variably persistent finely wooly indumentum, on young leaves light brown, sparse to moderately dense and matted, sometimes at least partially obscuring the leaf surface, on older leaves fading to grey-white and becoming less dense to glabrate, the trichomes terete to flattened in cross-section, with stalk 0.02–0.08 mm long, upper portion 0.3–1.5 mm long, the upper portions mostly curled and ascending; abaxial leaf cuticular features (Fig. 5-22) of moderate to strong relief, the surface between stomata elaborately ornamented with a reticulating pattern of grooves and ridges, with epidermal cell boundaries always evident and marked by an impressed groove or by a raised ridge with an impressed groove along its middle. Pedicels glabrous to densely to sparsely wooly-strigose at anthesis, often becoming glabrous in fruit. The outer two sepals 1.8–2.0 mm long, 1.5–1.7 mm wide, the inner three sepals

1.8–2.2 mm long, 1.7–2.4 mm wide, all sepals glabrous to moderately densely pubescent with persistent indumentum of light brown to red-brown T-shaped trichomes, wooly on the outer, sericeous on the inner. Corolla tube 1.5–1.8 mm long, lateral corolla lobe segments 1.8–2.2 mm long (from junction with adjacent lateral segment), 1.5–1.8

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mm long (from junction with median lobe). Stamens with filament 1.4–1.8 mm long.

Staminodes 1.7–1.9 mm long, sometimes equaling or exceeding the median corolla lobes. Ovary ca. 1–1.3 mm long, 1 mm wide, glabrous to densely pubescent at anthesis with a sericeous indumentum of straight, appressed, white to light brown T–shaped trichomes, the trichomes longer on distal part of ovary. Fruit 6.3–11 mm long, 6–10 mm wide. (See Fig. 5-24).

Distribution and habitat. Sideroxylon reclinatum subsp. austrofloridense is a narrowly endemic taxon, found only in Miami-Dade, Monroe, and Collier Counties,

Florida, where it is restricted to pine rocklands, marl prairies, and edges of tropical rockland hardwood hammocks (Fig. 5-25). The southern tip of peninsular Florida, including the Florida Keys, is one of the state's hotspots of rare and endemic plant taxa

(Ward 1979; Chaplin et al. 2000). Unusual for the continental United States, the flora of this region is dominated by tropical species of West Indian origin. For a list of associated species, see Corogin & Judd (2014). The range of Sideroxylon reclinatum subsp. austrofloridense is centered in Miami-Dade County on the Miami rock ridge, which extends from Long Pine Key in the Everglades northward through urban Miami to the Miami River. The taxon is locally abundant at Long Pine Key, and is found at Pine

Island, and around the edges of Royal Palm Hammock and Paradise Key, in

Everglades National Park. It has been collected in several extant rockland fragments in the urbanized areas of the Miami rock ridge as far north as the Miami City Cemetery

(1944, A. Korsakoff s.n.). Historically, it was collected as far south as Key Largo (1948,

C.R. Jackson s.n.) and Flamingo (1924, J.K. Small 11537) in Monroe County. More recently it has been collected farther west and north at locations in Big Cypress National

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Preserve: Monument Lake in Collier County (2014, Sadle 630; 1998, Bradley 1547), and the Loop Road area (1964, Godfrey 63520) and Lostman's Pines area (2003,

Woodmansee 1121) in Monroe County (Hodges & Bradley 2006; Gann et al. 2014).

There are unvouchered reports of additional occurrences on the Miami rock ridge and in

Big Cypress National Preserve (Gann et al. 2014). All locations where Sideroxylon reclinatum subsp. austrofloridense has been collected have limestone bedrock either exposed at the surface or covered with only a thin layer of marl-based soil. These soils become more sandy toward the northwestern limits of the range, where S. reclinatum subsp. reclinatum is also found.

Phenology. Flowering April–May, fruit ripening June–July.

Common names. Everglades bully; Everglades buckthorn.

Conservation status. Sideroxylon reclinatum subsp. austrofloridense is a candidate for federal listing under the Endangered Species Act, under the common name "Everglades Bully" (USFWS 2013a). Although the main population of S. reclinatum subsp. austrofloridense is locally abundant and located on protected land, the U.S. Fish and Wildlife Service considers that a change in listing status is warranted but precluded by higher priorities (USFWS 2013b). The Institute for Regional

Conservation in Miami considers Sideroxylon reclinatum subsp. austrofloridense to be imperiled in south Florida (Gann et al. 2002, 2014). The pine rockland plant community is ranked critically imperiled both globally and in Florida by the Florida Natural Areas

Inventory (FNAI 2010). The pine rocklands of mainland south Florida once extended from Long Pine Key, the principal upland of Everglades National Park, northeastward along the Miami rock ridge as far as the Miami River, but urban and agricultural

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development has extirpated the native plant cover from all but Long Pine Key and a handful of small patches on private land or preserved as county parks (Olmsted et al.

1983; Bradley & Martin 2012). The chief immediate threats to S. reclinatum subsp. austrofloridense and its habitat are fire suppression and exotic species invasion.

Recommended conservation actions currently consist of habitat protection and maintenance by prescribed fire, control of invasive non-native species, efforts to acquire, monitor and protect remaining rockland fragments, and continued monitoring and study to watch for adverse effects that may arise from human activities such as water management policies and the Everglades restoration program (Gann et al. 2002;

FNAI 2010; USFWS 2013b).

Long-term sea level rise due to climate change also threatens the rockland flora.

Discovery of 8600-year-old submerged remains of pine trees 60 km west of Key West suggests that since the last glacial maximum (ca. 18,000 years before present), south

Florida pinelands have been in retreat as rising seas have inundated a once more extensive range; during the past century that retreat has continued measurably in the

Florida keys (Ross et al. 1994, 2009). As sea level rises, outright inundation is preceded by saltwater intrusion, which is currently producing changes to the species composition of vulnerable south Florida coastal habitats (Saha et al. 2011). Sea level is predicted to rise 1–2 m by 2100 (URS Corporation et al. 2007; Saha et al. 2011), and elevation at

Long Pine Key is 2 m or less. Sideroxylon reclinatum subsp. austrofloridense and its rare and endemic associates clearly face an uncertain future.

Specimens examined. USA. Florida. Collier Co.: Big Cypress National

Preserve, Monument Lake Campground, 22 Mar 1998, Bradley 1547 (FTG); Big

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Cypress National Preserve, Monument Lake Campground, marl prairie E of rd. to campground and N of radio tower service rd., UTM 17N 488611E, 2860886N, 29 May

2014, Sadle 630 (FNPS). Miami-Dade Co.: Everglades National Park, Long Pine Key,

2.5 mi W of campground T5,7S, R37E, SW1/4 Sec 32, 11 May 1999, Anderson 18620

(FSU); Everglades National Park, Long Pine Key near Mosier Hammock, 11 May 1999,

Anderson 18621, 18622 (FSU); Everglades National Park, bordering Pine Island Rd.,

0.3 mi S of main road, T58S, R37E, SW1/4 Sec 12, 11 May 1999, Anderson 18623

(FSU); Frog Pond, just W of C-111 canal, 3.5 miles N of Rt 27, ca. 4 mi W of Florida

City, 11 May 1999, Anderson 18625, (FSU); Lucille Hammock, 0.9 mi W of 217th Ave., ca. 3 mi W of Florida City, T57S, R38E, SW1/4 Sec. 29, 11 May 1999, Anderson 18629

(FSU); Pine Ridge Sanctuary, 21100.SW 300 St., ca. 2 air mi NW of Homestead, 11

May 1999, Anderson 18631 (FSU); Everglades National Park, Long Pine Key, May

1908, E.A. Bessey 75 (A); Everglades, Paradise Key, 5 May 1908, E.A. Bessey 2 (G);

Frog Pond, 25°26.837'N, 080°33.757'W, 6 Aug 1997, Bradley & Woodmansee 422

(FTG); NW of Royal Palm Park, 3 May 1938, Buswell s.n. (FTG); Everglades National

Park, Long Pine Key, N and W of campground, 26 Jul 2011, 25.40341°N, 080.65797°W,

Corogin 1045 (FNPS); ibid., 25.40335°N, 080.65838°W, Corogin 1046 (FNPS); ibid.,

25.40244°N, 080.66216°W, Corogin 1047 (FNPS); ibid., 25.40138°N, 080.66822°W,

Corogin 1048 (FNPS); ibid., 25.40172°N, 080.66997°W, Corogin 1049 (FNPS); ibid., 27

Jul 2011, 25.40463°N, 080.67649°W, Corogin 1050 (FNPS); ibid., 25.40342°N,

080.67348°W, Corogin 1051 (FNPS); ibid., 28 Jul 2011, 25.40359°N, 080.66031°W,

Corogin 1052 (FNPS); ibid., 25.40442°N, 080.65965°W, Corogin 1053 (FNPS); ibid.,

25.40061°N, 080.66123°W, Corogin 1054 (FNPS); ibid., 25,40061°N, 080.66103°W,

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Corogin 1055 (FNPS); ibid., 25.40096°N, 080.66393°W, Corogin 1056 (FNPS); ibid., 11

May 2013, 25°24'5.6"N, 080°39'35.9"W, Corogin 1273 (FNPS); ibid., 25°24'6.2"N,

080°39'38"W, Corogin 1274 (FNPS); ibid., 25°24'7.4"N, 080°39'42.9"W, Corogin 1275

(FNPS); ibid., 25°24'6.2"N, 080°40'11.9"W, Corogin 1276 (FNPS); ibid., 26 Jul 2013,

25°24'6.2"N, 080°40'11.9"W, Corogin 1286 (FNPS); Everglades National Park, Long

Pine Key, 9 Jul 1961, Craighead s.n. (USF); Everglades National Park, Long Pine Key near Redd Hammock, 22 Dec 1958, Craighead s.n. (FLAS); West Avocado Drive, 15

Feb 1955, F.C.C. 352 (FTG); near Naranja, 21 Jan 1937, Fennell 301 (A); Everglades

National Park, Royal Palm Hammock, 6 May 1928, Fisher 54 (US); Everglades National

Park, Long Pine Key, 18 Apr 1964, Godfrey 63460 (FSU); Everglades National Park,

3.2 mi N of Rock Reef Pass, 17 Apr 1964, Godfrey 63394 (FSU); Everglades National

Park, Long Pine Key, 4 May 1979, Godfrey 77025 (FSU); Everglades, N end Paradise

Key, 29 Mar 1909, R.M. Harper 110 (G); Everglades National Park, pinelands auto trail,1.5 mi W of Long Pine Key rd., 21 Jun 1975, Hill & Harvey 3215 (FTG); Miami City

Cemetery, 30 Mar 1944, Korsakoff s.n. (FLAS); Larry & Penny Thompson Park,

25.59887°N, 080.40135°W, 26 May 2004, Possley 67 (FTG); Quail Roost Pineland,

25.57630°N, 080.42754°W, 26 Apr 2011, Possley 109 (FTG); Sunny Palms Pineland,

25.42835°N, 080.52053°W, 26 May 2011, Possley 110 (FTG); Everglades National

Park, Paradise Key, 3 May 1920, Rehder 898 (A); Everglades National Park, marl prairie near edge of Royal Palm Road, N of Royal Palm Hammock, UTM 17N 538844E,

2808076N, 28 May 2014, Sadle 627, 628 (FNPS); Everglades National Park, marl prairie adjacent to wet pine rocklands at western edge of Pine Island, just N of Main

Park Rd., UTM 17N 541041E, 2808752N, 28 May 2014, Sadle 629 (FNPS); Everglades

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National Park, Royal Palm Hammock/Paradise Key and vicinity, 21 Sep 1917, Safford &

Mosier 22 (US); Everglades, S of Long Key, 18 Jan 1909, J.K. Small & J.J. Carter s.n.

(FTG); Hammocks, Homestead to Big Hammock Prairie, 15 Feb 1911, J.K. Small & J.J.

Carter s.n. (FTG); Everglades, Camp Jackson to Camp Longview, 21 Feb 1911, J.K.

Small & J.J. Carter s.n. (FTG); Everglades National Park, Long Pine Key, 6 May 1904,

J.K. Small & P. Wilson s.n. (US); Everglades National Park, Long Pine Key, 5 Apr 1968,

Sullivan s.n. (FTG); Everglades National Park, Long Pine Key near picnic ground, 8 Apr

1971, Tomlinson & Avery s.n. (FTG); Everglades National Park, 4.6 mi S of park entrance on main rd. to Flamingo, 23 Apr 1958, Traverse 592 (G); Everglades, Long

Pine Key, 5 Jul 1950, Woodbury s.n. (FTG). Monroe Co.: Near Fla. Rt 94, 3.8 mi W of

Dade-Monroe County line, 19 Apr 1964, Godfrey 63520 (FSU); Key Largo, 27 Feb

1948, Jackson s.n. (FTG); Hammock back of Flamingo, Cape Sable region, 21 Jul

1924, J.K. Small et al. s.n.(G); Big Cypress National Preserve, Lostmans Pines area, ca. 11.13 km S of Loop Rd. (State Rt 94), 17.9 km W of the Miami-Dade County line, just N of border with Everglades National Park, 25.66063° N, 081.04996° W, 26 Mar

2003, Woodmansee 1121 (FNPS).

Sideroxylon reclinatum Michx. subsp. reclinatum, Fl. Bor. Amer. 1:122. 1803. Bumelia reclinata (Michx.) Vent., Choix Pl. pl. 22. 1803. Bumelia lycioides (L.) Pers. var. reclinata (Michx.) A. Gray, Syn. Fl. N. Amer. 2(1): 68. 1878. TYPE: U.S.A. GEORGIA: without data, A. Michaux s.n. (HOLOTYPE: P–not seen; ISOTYPE: GH–internet image!)

Bumelia microcarpa Small, Bull. New York Bot. Gard. 1: 440. 1900. TYPE: U.S.A. FLORIDA. ALACHUA CO.: Gainesville, Mar, Jun 1876, Garber s.n. (HOLOTYPE: NY– internet image!; ISOTYPE: US!).

Shrub, single to many-stemmed, 0.5–3 m tall, occasionally a small tree to 4 or 5 m tall, Indumentum light brown to blonde, the T-shaped trichomes terete and hollow

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(occasionally flattened) in cross-section, the top portions generally straight and appressed, but sometimes curled and ascending. Young twigs (long shoots) green to red-brown, glabrous, or sometimes sparsely pubescent with straight, mostly appressed trichomes and quickly becoming glabrous. Mature twigs usually remaining relatively smooth, the surface fading to grey-brown by second season, woody galls occasionally present on older twigs. Petioles 2–7 (–10) mm long on short shoots, glabrous, or young petioles having a sparse, blonde to light brown, deciduous indumentum; leaf blades on short shoots 10–40 (–70) mm long, 4–26 (–37) mm wide, narrowly to broadly obovate, sometimes elliptic, flat; abaxial leaf surface glabrous, young leaves sometimes very sparsely pubescent with quickly deciduous, fine blonde to light brown trichomes and becoming glabrous, trichomes sometimes persistent only along midvein, the trichomes

T-shaped, terete (rarely flattened) in cross-section, with stalk 0.02 mm long or less

(trichomes nearly sessile), upper portion 0.5–0.9 mm long, the upper portions mostly straight and appressed, sometimes curled and ascending; abaxial leaf cuticular features

(Fig. 5-21) of low to moderate relief, the surface between stomata relatively smooth and irregularly undulating, with epidermal cell boundaries obscure to evident, marked, if visible, by a raised ridge that lacks an impressed groove along its middle. Pedicels glabrous. The outer two sepals 1.3–2. mm long, 1.3–2. mm wide, the inner three sepals

1.2–2.2 mm long, 1.7–2.2 mm wide, all sepals glabrous, or with a few scattered trichomes basally. Corolla tube 1.3–1.7 mm long, lateral corolla lobe segments 1.7–2.2 mm long (from junction with adjacent lateral segment), 1.2–1.5 mm long (from junction with median lobe). Stamens with filament 1.3–1.6 mm long. Staminodes 1.8–2.2 mm long, rarely equaling or exceeding the median corolla lobes. Ovary ca. 0.8–1.1 mm long,

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0.7–1.1 mm wide, glabrous at anthesis, or with a few pale trichomes basally. Fruit 7.5–9 mm long, 7.3–8 mm wide. (See Fig. 5-24).

Distribution and habitat. Found throughout most of Florida, except for Miami-

Dade Co. and a few northern counties, and occurring in a few counties in southern

Georgia; infrequently collected in Alabama and Louisiana (Fig. 5-23). A plant of wet to mesic, sandy to calcareous habitats, usually in association with temperate hardwood species.

Phenology. Flowering April–June, fruit ripening July–August.

Common names. Florida bully; smooth bumelia.

Specimens examined. USA, Alabama. Bullock Co.: Hwy 53 at W side of

Double Creek, N of rd, 3 Jun 1999, Diamond 11578 (TENN). Clarke Co.: Without location data, 31 Oct 1997, Whetstone 19009 (JSU). Dale Co.: Without location data, 3

Jun 1998, Rundell 584 (TROY). Mobile Co.: Edge of salt marsh, Cedar Point, N side of

Dauphin Island, 2 Jun 1972, Kral 47105 (AUA). Florida. Alachua Co.: Payne’s Prairie

State Park, near parking lot at LaChua trailhead, 29°36’37.9”N, 082°18’16.1”W, 1 Aug

2012, Corogin 1100 (FLAS); along River Styx where it flows into Orange Lake (N end of lake), 3 May 1983, Judd 3307 (FLAS). Brevard Co.: S side of US 192, 7 mi W of

Melbourne, 20 May 1979, Baltzell 10794 (FLAS). Broward Co.: Cypress Creek

Hammock near Margate, 28 Apr 1977, Correll 48485 (FTG); Fern Forest Nature Center,

Coconut Creek, T59S, R42E, Secs. 5/6, 8 May 2001, Howell 389 (USF). Charlotte Co.:

Prairie Creek Preserve, 7.6 km E of US 17, 1.6 km S of DeSoto Co. line, W floodplain of

Prairie Creek, 27°01'13"N, 81°52'53"W, 9 Oct 2011, Franck 2878 (USF). Calhoun Co.:

Apalachicola River floodplain at N side of Ocheesee Landing, 30.58244°N,

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84.96541°W, 16 Mar 2013, Anderson 26893 (FSU). Citrus Co.: Hollins zone 27, edge of borrow-pit pond, 1 May 2001, Scanlon 211 (FLAS). Collier Co.: Kissimmee Billy, N of

Alligator Alley, 28 Apr 1976, Correll 47094 (FTG); Big Cypress National Preserve, off

Cypress Rd, 6.2 mi E of Turner River Rd, S of Alligator Alley, 27 Jul 1989, DeLapp 521

(FNPS); Deep Lake, 3 mi N of Jerome, 19 Apr 1964, Godfrey & Ward 63562 (FSU); 2 mi E of Collier-Seminole State Park, by US 41, 1 May 1979, Godfrey 77002 (FSU);

Cross State Turnpike, Miles City, W of FL 29, 27 May 1966, Lakela & DeBoer 29857

(USF); Deep Lake, 3 mi N of Jerome, 1 mi E of FL 29, 21 Aug 1965, Lakela & Laker

29124 (USF); Fakahatchee Strand State Preserve, 0.3 mi N of Gate 1, W of James

Scenic Drive, 22 May 1999, Pires FS0356 (USF); Fakahatchee, margin of hammock, 6

Mar 1965, Lakela & Long 28181 (USF); off rd to Bird Sanctuary, Corkscrew, 7 Mar

1965, Lakela & Long 28215 (USF). Columbia Co.: Close to the Santa Fe River, Three

Rivers Estates, S of US Rt 27, 25 Aug 1984, Godfrey 81581 (FLAS). Dixie Co.: Pine flatwoods 5 mi N of Hines, 13 Jun 1956, Kral & Redfern 2658 (FSU). Escambia Co.:

NE of Cantonment, along E side of south end of Quinnette Lake, on small islet, 14 Jun

1998, Burkhalter 15938 (FSU). Flagler Co.: N side of Fla. 305, 5.7 mi E of Volusia Co. line, S32, T13S, R29E, 7 Jul 1965, Ward 4725 (FLAS). Gadsden Co.: Banks of

Apalachicola River at Aspalaga, 7 Jul 1955, Godfrey 53598 (G); by County Rd. 269, 0.5 mi from railroad crossing at River Junction, 1 Jul 1991, Godfrey 84198 (TENN);

Chattahoochee, bluff along Apalachicola River overlooking Clyde T. Hopkins Municipal

Park on River Landing Rd., 8 May 1995, MacDonald 8652 (TENN). Gilchrist Co.:

Banks of Suwannee River, near public boat ramp W of Otter Springs, 5 Jun 2012,

Corogin 1060 (FLAS); NW of Trenton, ca. 1 mi W of dead-end of County Rd. 344, at

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Suwannee River, ca. 0.5 mi W of Hart Springs Park, 6 Sep 2003, Judd 8047 (FTG).

Glades Co.: NW of Lake Okeechobee, in Paradise Run, an area S of Lock S-65E of

Kissimmee River (C38 Canal), 3 Sep 1981, Coile 2463 (GA). Hamilton Co.: Road between Ellaville and Jennings, 11 Apr 1940, West & Arnold s.n. (FLAS). Hardee Co.:

At jct of Paynes Creek and Peace River, TRS: NE1/4, SW1/4, S9, T33S, R25E, 24 Jul

2008, Gandy PC0138 (USF). Hendry Co.: Rt S-846, 19 mi S of 832-S-832 intersection, cattle country, 2 May 1975, Hill 2917 (FTG); Big Cypress Reservation, 8 May 1959,

Sturtevant 146 (US). Hernando Co.: Along W side of Croom Rd, 0.7 mi N of FL 50, ca.

3.5 mi S of Croom, T22S, R21E, Sec. 32, SE of NE, 10 Jun 1984, Hansen 9955 (USF).

Highlands Co.: Highlands Hammock State Park, 19 May 1982, Correll 53953 (USF).

Hillsborough Co.: Bottomlands of tributary to Hillsborough River, ca. ½ mi N of Fowler

Ave jct with Morris Bridge Rd, 28 Apr 1963, Lakela 25901 (USF). Jackson Co.:

Marianna Caverns State Park, at boat ramp, Chipola River, T5N, R10W, Sec. 21, NW of

SE, 5 Jul 1979, Hansen & Richardson 5949 (USF). Jefferson Co.: Woods at jct of

Wacissa & Aucilla Rds., 15 Mar 1939, Exploration Party 1939 (FLAS). Lafayette Co.:

Opposite Branford along Suwannee River, 20 May 1941, West & Arnold s.n. (FLAS).

Lake Co.: Along Sulphur Run, ca. 0.6 air mi SE of Lake Jordan, 1.5 air mi ESE of

Cassia, ca. 14.9 air mi ENE of Eustis, Seminole State Forest, Pine Lakes 7.5’ Quad,

NEQ, SEQ, Sec. 31, T18S, R29E, 28°52’36”N, 81°26’37”W, 18 Oct 1994, Orzell &

Bridges 23335 (USF). Lee Co.: Fort Myers, 26 Apr 1934, Buswell s.n. (FTG); Twelve

Mile Canal, red soil area, Fort Myers, 16 May 1928, J.K. Small s.n. (FSU, FTG). Leon

Co.: Ca. 2 mi S of Talquin Dam, above slough of Ochlochonee River, S29-30, T1S,

R4W, 8 May 1966, McDaniel 7483 (FLAS). Levy Co.: Manatee Springs State Park, 20

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May 1966, Godfrey 67679 (USF); ca. 2 mi E of Rosewood, 14 May 1977, Kral 60052

(USCH). Liberty Co.: Apalachicola Bluff country at Aspalaga, 25 Jul 1956, Kral &

Godfrey 3086 (FSU). Madison Co.: Wooded high bank of Withlacoochee River, vicinity of Blue Spring, by FL Rt 6, S of Madison, 13 Jul 1984, Godfrey 81473 (FSU). Manatee

Co.: Wingate Creek State Preserve, NW ¼, SE ¼, SE ¼, S7, T35S, R22E, 11 Sep

1997, Becker & Hattaway WC0289 (USF). Marion Co.: Ocala National Forest, ca. 0.3–

0.4 mi N of intersection of Hwy 40 and Co. Rd 315, 20 Apr 1985, Ruff 85-128 (FLAS).

Martin Co.: Jonathan Dickinson State Park, upper Kitching Creek area, 2 Apr 1977,

Popenoe 838 (FTG). Monroe Co.: Big Cypress National Preserve, near Pine Crest, along Loop Rd. 94, 28 Apr 1974, Correll 42244 (FTG); Big Cypress National Preserve,

Gum Slough area, 16 km S of US 41 (Tamiami Trail) at Monroe Station, 5.8 km SW of

Loop Rd (SR 94), 25.72048°N, 081.10416° W, 23 Apr 2003, Woodmansee 1149

(FNPS). Okeechobee Co.: Yates Marsh, future site of Cypress Energy power plant, 2.5 mi SW of US 98, 8 mi NW of Okeechobee, Taylor Creek SW Quadrangle, 27°18’14”N,

80°57’10”W, T36S, R34E, Sec 29, 24 Mar 1992, Burckhalter 2083 (LSU). Orange Co.:

Sandy soil, Windermere, 24 Jun 1929, Vasker s.n. (FLAS). Osceola Co.: Cypress swamp along Bull Creek, N of Loop Rd and N of bridge, Bull Creek Wildlife Mgmt Area,

22 mi W of I-95, 4 mi E of SR 441 and SR 192 intersection, via Crabgrass Rd, Sec. 9,

T28S, R34E, Deer Park Quad, UTM 506996, 3104665, 12 Jun 2007, Slaughter 15657

(USF). Palm Beach Co.: Yamato Scrub Natural Area, ca. 0.25 mi E of Congress Ave.,

N of Clint Moore Rd., 26°24.58'N, 80°05.944'W, 12 May 1998, Bradley & Woodmansee

977 (FTG). Pasco Co.: Bordering freshwater marsh behind a Walmart store ca. 400 ft

W of US 19, TRS: R16E, T25S, S29, NE ¼ OF NE ¼, 10 May 2004, vanHoek &

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O'Connor WB0505 (USF). Pinellas Co.: Brooker Creek Preserve, ca. 5 mi NNE of

Oldsmar, T27S, R16E, Sec. 36, SW ½, 29 Apr 1993, Hansen 12060 (USF). Polk Co.:

Colt Creek State Park, ca. 2.6 km SE of FL 471 bridge over the Withlacoochee River, ca. 5.3 km NNE of jct FL 471 and US 98, 28°17’38.4”N, 82°2’23.3”W, 15 Apr 2008,

Kunzer 2362 (USF). Sarasota Co.: Churchill Ranch on Border Rd, part of Deer Prairie

Creek Preserve, ca. 2.3 km ENE of jct I-75 and C-777, 27°07'03"N, 82°19'40"W, 30 May

2007, Franck 187 (USF). Sumter Co.: Ca. 9.5 map km SW of Bushnell, on S side of

Co. Rd. 673 (W of Webster), ca. 1.7 km E of I-75, just E of jct with Co. Rd 683D, 6 Nov

2007, Abbott 23723 (FLAS). Suwannee Co.: Little River Wildlife Mgmt Area, Brantley

Tract, north of Branford on US 129 to O'Brien, then 3.4 mi W on Co. Rd 349 to public entrance, then 0.4 mi S to powerline, then 1.5 mi SSW to parking lot at river, then SE along upper bank of river, 30°00'24"N, 82°59'41'W, 4 June 2007, Abbott 22631 (FLAS).

Taylor Co.: Near Steinhatchee River, by US Rt 98/19, NW of Cross City, 19 May 1984,

Godfrey 81312 (FLAS, FSU). Volusia Co.: N Hitchens Island, SE Lake George, 1.6 mi

E of St Johns River, 5 mi N of SR 40 (Astor, FL), Sec. 12, T51S, R27E, Astor Quad,

UTM 447319, 3231570, 26 Mar 2008, Slaughter et al. 16315 (USF). Wakulla Co.: St.

Marks National Wildlife Refuge, along Port Leon Rd, W of jct with East River Dike Rd,

30.13975°N, 84.174175°W, 26 Apr 2007, Anderson 22961 (FSU). Georgia. Baker Co.:

Big Cypress Hammock, 29 Aug 1946, Ford & Thorne s.n. (TENN); Hammock no. 20, E side of Ichauwaynochaway Creek, S of SR 200, Ichauway Plantation, 1 Sep 1986,

Gholson 11740 (FSU). Charlton Co.: St. Mary’s River, at Stanley’s Landing, 4 Aug

1959, Cypert 229 (GA). Decatur Co.: Just N of boat ramp area on E side of Lake

Seminole, N of Jim Woodruff Dam, 2 Aug 1983, Nelson 2683 (FSU). Miller Co.: Ca. 4.2

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air mi WNW of Colquitt, above Cypress Creek, just N of Griggs-Lucille Rd (S1968 OR

Co. Rd 95), ca. 1.8 rd mi W of jct US Hwy 27, 1 Aug 1996, Allison 9362 (FSU). Peirce

Co.: Sandy ridge on US 82, N of Satilla River, 7 May 1959, Cypert 193 (GA). Seminole

Co.: Near Big Pond, Trawick Place, 7 mi S of Iron City, 12 Sep 1947, Thorne 6621

(GA). Louisiana. Cameron Parish: Roadside of Cameron Parish Rd 388 just off LA 82, ca. 7.7 mi W of Oak Grove, Secs 66 & 67, T14S, R9W, 22 Oct 1983, Dutton & Taylor

757 & 6188 (FSU).

Discussion. Sideroxylon reclinatum, along with S. lanuginosum, named by

Michaux (1803), were the third and fourth North American species of Sideroxylon to be described. Sideroxylon reclinatum is a mostly low-growing thorny shrub (occasionally a small tree) of calcareous or sandy, wet to mesic wooded habitats of Florida and the outer coastal plain from southern Georgia to Louisiana. Cronquist (1945) recognized two varieties, Bumelia reclinata (Michx.) Vent. var. reclinata, and B. reclinata var. rufotomentosa (Small) Cronquist, the latter having been previously recognized as a species (B. rufotomentosa) by Small (1900). Whetstone (1985) named a third variety, B. reclinata var. austrofloridensis Whetstone ("Everglades buckthorn"), based on morphologically distinct collections from subtropical rocklands in the vicinity of Long

Pine Key in the Florida Everglades. Varieties rufotomentosa and austrofloridensis were transferred to Sideroxylon by Kartesz and Gandhi (1990), and recognized as S. reclinatum subsp. rufotomentosum (Small) Kartesz & Gandhi, and S. reclinatum subsp. austrofloridense (Whetstone) Kartesz & Gandhi, respectively. Based on consistent differences in morphology, habit, and habitat, Herring and Judd (1995) recognized S. reclinatum subsp. rufotomentosum as a distinct species, Sideroxylon rufohirtum Herring

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& Judd, (see Godfrey 1988), and this designation is here recognized. Thus Sideroxylon reclinatum, as currently circumscribed, comprises two subspecies.

The widespread subspecies reclinatum is most easily distinguished from its relatives by being a glabrous plant of generally low stature with small leaves, found in mesic to wet habitats. Pubescence on young twigs and leaves is quickly deciduous if present at all, persisting sometimes only along the abaxial midvein, and the ovary is glabrous or with only a few scattered trichomes (Fig. 5-24). The narrowly endemic subspecies austrofloridense was originally diagnosed by Whetstone (1985) based on specimens from the population on pine rockland and marl prairie habitat at Long Pine

Key in Everglades National Park, Florida. Plants from this population are morphologically quite distinct, readily distinguishable at a glance from subspecies reclinatum by the persistent dense, matted wooly brown pubescence on the abaxial leaf surfaces and often also on the sepals and pedicels, with ovaries densely to sparsely pubescent at anthesis (Fig. 5-24). Delimitation of subspecies austrofloridense thus seemed very straightforward, and its range was considered limited to the vicinity of

Long Pine Key. However, my recent study (Corogin & Judd 2014), utilizing scanning electron microscopy (SEM), along with close examination of specimens including more recent collections, and extensive field observations of both subspecies, suggest that the two subspecies are most reliably distinguished by differences in the micromorphology of the abaxial leaf epidermis, and that the extent of distribution of subsp. austrofloridense, while limited to extreme southern peninsular Florida, is somewhat larger than was previously supposed.

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SEM images of the abaxial leaf cuticular surfaces of Sideroxylon species reveal some useful differences in the surface features of these taxa. Previous SEM study has shown that taxa of Sideroxylon can be reliably distinguished by such characters

(Anderson 1996). Stomata in all cases are recessed inside dome-like chambers with generally elliptical openings. In both subspecies of Sideroxylon reclinatum, each chamber opening is surrounded by a series of irregularly concentric cuticular ridges, often also with ridges radiating out perpendicularly from the opening. A difference is noted, however, between the subspecies, in the overall relief of the cuticular ornamentation, and in the appearance of the epidermal cell boundaries. In subspecies reclinatum, the surface between stomata is relatively smooth and irregularly undulating, cuticular ornamentations are of low to moderate relief, and epidermal cell outlines, if visible at all, are marked by a smooth, raised ridge that lacks an impressed groove along its middle (Fig. 5-21, see arrows). In subspecies austrofloridense, by contrast, the surface between stomata is elaborately ornamented with a reticulating pattern of grooves and ridges, cuticular ornamentations are of moderate to strong relief, and epidermal cell outlines are always prominently visible and marked by an impressed groove, or by a ridge with a groove along its middle (Fig. 5-22, see arrows). This latter set of characters was found on all persistently pubescent specimens of subspecies austrofloridense from Long Pine Key and nearby remnants of rockland habitat along the urbanized Miami rock ridge. But surprisingly, these characters were also found on specimens outside this original narrow range (and some within it) having a sparser and less persistent leaf indumentum, appearing glabrous or nearly so, many of them most closely resembling subspecies reclinatum. Whether pubescent or glabrous, however, all

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of the plants I examined that occur within the expanded range of subspecies austrofloridense as defined above, exhibit the micromorphological characters of subspecies austrofloridense. Plants I examined from outside this range exhibit the micromorphology of subspecies reclinatum. The only place where plants of both micromorphological types occur together is where the ranges of the two subspecies come into contact, at the western fringes of the range of subspecies austrofloridense, in

Big Cypress National Preserve in Monroe and Collier Counties (Fig. 5-25).

It is clear that Sideroxylon reclinatum subsp. austrofloridense is easily and reliably diagnosable from S. reclinatum subsp. reclinatum by a set of distinct character state differences at the micromorphological level. At the macromorphological level, the distinction is less reliable, as glabrescent specimens of subspecies austrofloridense can be confused with the typically glabrous subspecies reclinatum. The two taxa are also separated eco-geographically. The more widespread subspecies reclinatum ranges in coastal plain areas from south Georgia west to Louisiana, and throughout Florida as far south as Broward County in the east, and Collier and Monroe Counties in the west, and its habitats feature sandy soils often with limestone near the surface. Subspecies austrofloridense, on the other hand, is a narrow endemic taxon, its range restricted to subtropical rockland and marl prairie habitats in a well-defined area of extreme southeast peninsular Florida, and its habitats feature exposed limestone, or limestone thinly overlain with clayey marl soils. The two subspecies are thus clearly defined, and essentially allopatric. Because S. reclinatum subsp. austrofloridense is a narrow endemic restricted to a particular habitat and geographical area, and because it is allopatric with respect to subspecies reclinatum and diagnosable from it, I consider

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Sideroxylon reclinatum subsp. austrofloridense to be worthy of taxonomic recognition.

Since the diagnosing characters are micromorphological and somewhat cryptic, and pubescence characters intergrade, I consider recognition at the subspecific rank to be appropriate. Thus the current classification of these plants is maintained, but the distribution of subspecies austrofloridense is broadened, and it is best diagnosed by the newly discovered micromorphological features.

Sideroxylon reclinatum, along with S. macrocarpum and S. rufohirtum, form the

Sideroxylon reclinatum complex; they have been presumed closely related based on morphological similarities such as low habit, small leaves with prominent vein reticulum, and abaxial leaf pubescence that is usually sparse, if present, and often deciduous.

Morphological phylogenetic analysis (Chapter 3) supports this supposition, indicating that these four species form a clade within section Frigoricola. This analysis also supports S. reclinatum, both subspecies, as a cladospecies, on the basis of pubescence of young twigs being absent or quickly deciduous. The cladospecies is sister to a clade containing S. rufohirtum and S. macrocarpum.

7. Sideroxylon rufohirtum Herring & Judd, Castanea 60:358. 1995. Bumelia rufotomentosa Small, Bull. New York Bot. Gard. 1:440. 1900. Bumelia reclinata (Michx.) Ventenat var. rufotomentosa (Small) Cronquist, J. Arnold Arbor. 26:456. 1945. Sideroxylon reclinatum Michx. subsp. rufotomentosum (Small) Kartesz & Gandhi, Phytologia 68: 425. 1990. TYPE: U.S.A.: FLORIDA: HILLSBOROUGH COUNTY: Tampa, May 1876, A.P. Garber s.n. (HOLOTYPE: NY– internet image!; ISOTYPES: FLAS!; US, two sheets!).

Shrub, highly stoloniferous, frequently forming clonal patches of low-growing, profusely branching thorny shoots from woody underground stems, the patches often several meters long and wide, the shoots densely to sparsely disposed, typically not more than ca. 0.5m tall, rarely reaching heights up to 3m as many-stemmed shrubs with

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trunk diameters ca. 1–7 cm. Indumentum of unicellular T-shaped trichomes of distinctly red to red-brown color, symmetric or asymmetric, terete and hollow to flattened in cross- section, having a short stalk and a longer upper portion of varying length, the upper portion curled and ascending. Vegetative buds densely wooly-pubescent with short, straight to bent to curled, ascending, dark red-brown T-shaped trichomes, terete to flattened/twisted, the stalk 0.02–0.05 mm long, the top portion 0.15–1 mm long. Young twigs (long shoots) terete, 0.8–2. mm wide, densely and finely wooly-pubescent with red-brown T-shaped trichomes, the trichomes terete to flattened-twisted in cross- section, the stalk 0.03–0.1 mm, the top portion 0.3–1.1 mm, the hair tops straight to bent or curled and mostly ascending, the pubescence commonly persistent into the second season and sometimes longer, the twig surface green to dark red-brown, prominently dotted with lenticels; thorns often present at nodes, especially on young stems, thorns 0.3–2.5 cm long, the smaller ones slender and needle-like, some becoming short spur shoots or lengthening to become side branches. Mature twigs retaining some pubescence, becoming glabrous with age, fading to brown to grey- brown and developing short longitudinal and transverse fissures, lenticels evident, woody galls common, leaves clustered on stumpy brachyblasts (short spur shoots); internode length 4–26 mm. Leaves tardily deciduous, with petioles 2–8 mm long on young long shoots, 1–5 mm long on short shoots, the petioles canaliculate and sparsely to moderately wooly-pubescent with red-brown trichomes, becoming glabrate; blade

1.5–3.6 (–7.1) cm long, 0.8–2.6 (–3.2) cm wide on young long shoots, oblanceolate to broadly obovate to suborbicular, 0.7–4.5 cm long, 0.44–1.4 cm wide on short shoots, oblanceolate to broadly obovate, occasionally suborbicular, flat, coriaceous, the apex

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rounded, occasionally retuse, the base acute to narrowly cuneate, the margin entire and slightly revolute; venation conspicuously finely reticulate, the primary venation pinnate, the secondary venation brochidodromous, with secondary veins slightly decurrent, branching off midvein in opposite to subopposite to alternate arrangement, ± in 6–10 irregularly spaced pairs, with an intersecondary vein occasionally occurring between secondaries, its length ca. 50% the length of the secondaries, its distal course reticulating, the tertiary veins irregular reticulate, the quaternary veins irregular reticulate, the quinternary veins irregular reticulate to freely ramifying, areolation moderately developed, the marginal ultimate venation looped; adaxial surface dark green, glossy, young leaves often with a sparse indumentum of quickly deciduous red trichomes, the vein reticulum conspicuously evident, flush to raised (fresh leaf), raised or sometimes impressed (dried leaf), giving the surface a textured, veiny appearance; abaxial surface with wooly indumentum of red to red-brown trichomes, often giving surface a distinctly reddish hue, young leaves often heavily but loosely covered, the trichomes gradually sloughing as leaves age, the surface becoming glabrate, trichomes persisting longest along midvein, the trichomes terete or flattened in cross-section and often twisted, T-shaped, with stalk 0.05–0.15 mm long, top portion 0.2–1.3 mm long, the top portions curled and ascending, the vein reticulum evident; stomata (Fig. 5-26) recessed inside dome-like chambers raised markedly from the leaf surface, the chamber openings wide, elliptical to nearly round, the guard cells clearly visible through the opening, each opening centered on the flat to slightly cup-shaped surface of a raised, broad donut-shaped structure ornamented with a few irregularly concentric epicuticular ridges, the outermost ridge forming a striking border around the top of the

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structure, the surface between stomatal complexes generally smooth, epidermal cell boundaries evident and marked by impressed grooves. Inflorescence a fascicle borne in a leaf axil, fascicles often clustered on short spur shoots in axils of fallen leaves, each fascicle having ca. 4–20 pedicellate flowers, the pedicels 1.5–6.5 (–9) mm long, glabrous, or sparsely wooly-pubescent distally and becoming glabrous in fruit. Calyx of

5 quincuncial, free sepals, the outer two sepals 1.6–2.2 mm long, 1.5–2 mm wide, ovate to suborbicular, the apex rounded, the margins entire, the inner three sepals 2–2.5 mm long, 1.8–2.2 mm wide, broadly ovate to suborbicular, the apex rounded; the margin entire to erose, with a broad membranous rim, sepals loosely wooly-pubescent only basally and along midrib with red-brown T-shaped trichomes, becoming glabrous in fruit, the trichomes all flattened in cross-section and highly twisted, the stalk 0.02–0.08 mm, the top portion 0.4–0.8 mm long. Corolla white, cyathiform, sympetalous, the tube

1.5–2.2 mm long, enclosed within the calyx; the lobes 5, exserted and spreading, glabrous, each with a median lobe and two lateral segments, the median lobe 1.5–2 mm long, 1.2–1.6 mm wide, ovate to suborbicular, clawed, cupped around a stamen, the lateral segments 2–2.5 mm long (from junction with adjacent lateral segment), 1.2–1.5 mm long (from junction with median lobe), 0.5–1.5 mm wide, lanceolate, margins erose.

Stamens 5, epipetalous, opposite the corolla lobes, exserted; filament 1.5–1.8 mm long,

0.2–0.4 mm wide, fixed at top of corolla tube, dilated proximally and narrowing toward anther attachment; anther 1.0–1.4 mm long, 0.5–0.7 mm wide, sagittate, ventrifixed at the point of the sinus, opening by two dorsal longitudinal slits. Staminodes petaloid, alternating with stamens, each staminode 2–2.3 mm long, nearly as long as median corolla lobes, 1.2–1.5 mm wide, deltoid to ovate, infolded, margin erose, translucent.

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Ovary superior, 5–(6 –) loculate, locules uniovulate with basal-axile placentation, ovary ca. 1 mm long, 0.9–1 mm wide, globose to ovoid, tapering abruptly to the style, pubescent at anthesis with dense, sericeous indumentum of straight, appressed, red- brown T-shaped trichomes, the trichomes longer on distal part of ovary; pubescence usually continuous around ovary, but sometimes occurring in five patches corresponding to the locules, the rest of the surface glabrous, style 1.1–1.8 mm long, glabrous, included. Fruit a berry, one (rarely 2)-seeded, 12.6 –15.4 mm long, 12.2–14.3 mm wide, subglobose, glossy, black to purplish-green when ripe, the surface minutely dotted, glabrous. Seeds 8–10.4 mm long, 6.2–8.9 mm wide, ellipsoid, the testa hard, smooth, glossy, the color variegated light tan mottled with darker brown spots; the hilum scar basal, usually bipartite, the larger part basal, oval to deltoid, 1.9–3 mm long, 2.0–3 mm wide, the smaller part abaxial to other part, shallowly U-shaped, 1.5–2.5 mm long,

0.4–0.7 wide, the bridge of testa separating the two parts very narrow or absent, the scar being the exposed portion of a hollow cavity under the testa extending a small distance around the basal end of the seed, the cavity filled, especially on the abaxial side, with a yellowish fatty substance. (See Fig. 5-27).

Phenology. Flowering late May to mid-July, fruit ripening September–October.

Common names. Rufous Florida Bully.

Distribution and habitat. Sideroxylon rufohirtum is endemic to Florida, found in well-drained sandy pyrogenic upland pine habitats in 17 counties of north, central, and western peninsula (Fig. 5-28). The growth habit of this species, with most of its woody biomass below the soil or leaf litter surface, is no doubt an adaptation to the periodic fires typical of its habitats. Sideroxylon rufohirtum is also sometimes found thriving along

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powerline rights-of-way and road shoulders, where regular mowing (instead of fire) apparently favors the low-growing plant over its taller competitors. Godfrey (1988) pointed out, and I have observed, that plants of S. rufohirtum do not appear to be particularly common even in habitats where one would expect to find them, and they are often difficult to spot in the field.

Illustrations. Godfrey (1988, Fig. 321, by Melanie Darst).

Specimens examined. USA. Florida. Alachua Co.: Near Kanapaha Prairie SW of Gainesville, 29.572°N, 082.426°W, 19 Jun 2009, Corogin 1000 (FLAS); near

Gainesville, along Rt 24, ca. 5 mi SW of jct with SW 75th St. (Tower Rd), 4 May 2000,

Judd s.n. (FLAS). Citrus Co.: Near Inverness, 3 Jun 1948, West & Arnold s.n. (FLAS).

Clay Co.: Impact Rd, 4 mi W of Ridge Rd, S21, T5S, R23E, 4 Oct 1995, Hall 2122

(FLAS). Columbia Co.: Ichetucknee Springs State Park, 4.5 mi NW of Fort White off

US 27, T6S, R16E, S18, 12 Jun 1993, Herring 1162 (FLAS); along U.S. Rt. 27 E of Fort

White, 4 Sep 1984, Gholson s.n. (FLAS). Dixie Co.: Lower Suwanee National Wildlife

Refuge, Yellow Jacket Rd., 7 May 2004, J. Barichivich s.n. (FLAS). Hamilton Co.:

Suwannee River State Park, NW of Live Oak, N of Ellaville, accessed N off US 90 and

Co. Rd 32, 30°22.7’23”N, 83°9.7’10”W, 16 Dec 2005, Abbott 20776 (FLAS). Hernando

Co.: Off of Hwy 301S at Ridge Manor, 28.49463°N, 82.17381° W, 18 May 2008, Majure

3236 (FLAS). Hillsborough Co.: By USF, Breinhouse area, Tampa, 20 May 1964,

Burditt s.n. (USF). Lake Co.: Along Railroad Grade Rd, 0.6 mi S of jct FSR 35, 25 Sep

1985, Christman 48 (FLAS); W of Lake Minneola, 19 Apr 1985, Daubenmire s.n. (USF);

Roadside on Hwy 19 about 200 yds S of jct with old 441, Tavares, 20 Sep 1971,

Wofford 71-558-A (TENN). Levy Co.: Along SR 24 E of Cedar Key, 22 Nov 1980, Judd

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2926 (FLAS). Manatee Co.: High pine land, 10 Jun 1922, Cuthbert s.n. (FLAS). Marion

Co.: T15S, R23E, Sec 7, in Silver River State Park, 12 Jun 1996, Anderson 16586

(FSU); S of Silver Springs, E of State Rt 35, N side of County Rd 314, SW ¼, Sec. 7,

T15S, R23E, 14 Oct 1987, Gholson 11901 (FLAS). Orange Co.: Near Conway, 8 Sep

1925, Clemons s.n. (FLAS). Pasco Co.: Sandy oak ridges, Tarpon Springs to Lake

Butler, 5 Aug 1953, Garrett s.n. (FLAS). Pinellas Co.: Dunedin Hammock, Dunedin, 11

Feb 1977, Genelle & Fleming 2595 (USF). Putnam Co.: Univ. of Florida Conservation

Reserve, Welaka, T12S, R26E, 27 Mar 1959, Ward 1206 (FLAS). Suwannee Co.: T5S,

R15E, Sec 19, 12 Jun 1996, Anderson 16582 (FSU); T5S, R14E, S19, ca. 5 mi N of

Ichetucknee Springs, Oct 1981, Simons 239 (FLAS).

Discussion. Sideroxylon rufohirtum was first described by J.K. Small (1900) as

Bumelia rufotomentosa. Cronquist (1945) reduced it to a variety of Bumelia reclinata (B. reclinata var. rufotomentosa), and this variety was transferred to Sideroxylon by Kartesz

& Gandhi (1990). Based on consistent differences from its relatives in morphology, habit, and habitat, Herring and Judd (1995) recognized S. reclinatum subsp. rufotomentosum as a distinct species, Sideroxylon rufohirtum Herring & Judd.

Sideroxylon rufohirtum shares similarities of habit, habitat and morphology with

S. macrocarpum (Nutt.) J.R. Allison, a Georgia endemic present in 13 counties of southeastern Georgia. Both S. rufohirtum and S. macrocarpum prefer dry sandy upland habitats, both are highly clonal and low-growing, rarely exceeding 1m in height, and they have large fruits (> 10 mm diameter), young stems pubescent through at least part of the first season, and abaxial leaf pubescence that is sparse and often persistent. The ranges of S. rufohirtum and S. macrocarpum are geographically separated by ca. 120

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miles of lowlands, a basin that includes the Okefenokee Swamp, which has lacked suitable habitat for sandy upland plants since it was formed in the late Pliocene or early

Pleistocene, when sea level rose to cover the area (Cohen et al. 1984). Because of their similarities, Allison (2006) hypothesized that S. rufohirtum and S. macrocarpum may be sister species, the two species perhaps vacariantly separated by the evolution of the

Okefenokee Swamp and associated lowlands. This sister species relationship is supported by morphological phylogenetic analysis (Chapter 3), which shows that S. rufohirtum and S. macrocarpum form a clade on the basis of their highly clonal, low- growing habit. The ranges of these plants are nested within the range of the gopher tortoise, Gopherus polyphemus, an important seed-dispersing animal in pyrogenic sandy upland communities of the southeastern coastal plain (Auffenberg & Franz 1982;

Diemer 1986). Allison (2006) speculated that the low stature and large fruit size of S. rufohirtum and S. macrocarpum suggests a possible coevolutionary relationship with the gopher tortoise. Their low stature and clonal habit are also probably an adaptation to the periodic fires that occur in their habitats, and the similarities could also be due to convergent evolution.

Of all the Sideroxylon species of the southeastern United States, only three inhabit upland habitats with deep sand soils that are pyrogenic, i.e., dependent upon periodic fire for their maintenance: S. tenax, S. rufohirtum, and S. macrocarpum.

Sideroxylon tenax, a plant associated with Atlantic coastal beach dunes, as well as inland Florida scrubs on former beach dunes, has a dense sericeous leaf indumentum, can reach considerable tree-size, and is not generally highly clonal. Fires in the coastal dune and inland scrub habitats are relatively infrequent, occurring roughly every 5–30

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years (Menges 2007; FNAI 2010). Sideroxylon tenax can re-sprout from its root system after these fires, but if fires are too frequent, the species will not persist. Sideroxylon rufohirtum and S. macrocarpum, unlike S. tenax, have the characters of sparse leaf pubescence, low stature, and highly clonal habit. Like S. tenax, these two species inhabit deep-sand upland habitats, but they prefer the more frequently-burning longleaf pine associations, where fires occur roughly every 1–5 years (Reinhart & Menges

2004). It is interesting to note that although S. rufohirtum, and S. macrocarpum share many similarities, scanning electron microscope (SEM) examination of abaxial leaf surfaces reveals that the stomatal structure of Sideroxylon rufohirtum is quite different from that of S. macrocarpum, looking rather more like that of S. tenax.

8. Sideroxylon macrocarpum (Nutt.) J.R. Allison, Sida 22:243–264. 2006. Bumelia macrocarpa Nutt., N. Amer. Sylva 3:37. 1849. Bumelia lanuginosa var. macrocarpa A. Gray, Syn. Fl. 2:68. 1878. TYPE: USA: GEORGIA: sandy hills not far from the Altamaha: T. Nuttall s.n. (LECTOTYPE: PH–internet image!– accession no. 1030290, the small fragment at top left only, which pierces Nuttall's original label).

Shrub, highly stoloniferous, frequently forming clonal patches of low-growing, profusely branching thorny shoots from woody underground stems, the patches up to several meters long and wide, the shoots densely to sparsely disposed, aerial stems generally less than 1 m tall and up to 5 mm thick, the underground stems much longer than aerial stems, and up to at least 10 mm thick. Indumentum of unicellular, blond to light brown, T-shaped trichomes, symmetric or asymmetric, terete and hollow to flattened-twisted in cross-section, having a short stalk and a longer top portion of varying length, the top portion straight to curled, sometimes kinked, appressed to ascending. Vegetative buds densely wooly-pubescent with curled, ascending, blonde to light brown T-shaped trichomes, the stalk 0 02–0.08 mm long, the top portions 0.3–1

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mm long. Young twigs (long shoots) terete, slender, 0.5–1.2 mm thick, the surface green, becoming red-brown, densely pubescent with blonde to light brown, appressed to ascending, T-shaped trichomes, the stalks 0.03–0.1 mm long, the top portions 0.7–

1.3 mm long, the pubescence persisting through the first season, the young twigs profusely thorny, thorns 0.2–1.5 cm long, slender and needle-like, appearing in leaf axils and often quickly lengthening into leafy, thorny side-branches. Mature twigs brown to gray, slender, 0.5–5 mm thick, surface sometimes mottled, developing short longitudinal and transverse fissures, lenticels evident, mature twigs typically profusely thorny, thorns as short as 2 mm or as long as 8 cm, having lengthened into leafy, thorny side branches, some leaves becoming clustered on stumpy brachyblasts; internode length

(1–) 5–15 (–20) mm. Leaves tardily deciduous, alternate and spirally arranged on young long shoots, becoming fascicled on brachyblasts on older stems, petioles canaliculate,

1–4 (–5) mm long on young long shoots, 0.5–3.5 mm long on short shoots, and moderately shaggy-strigose to glabrate; leaf blades on young long shoots (0.9–) 1.5–4

(–5) cm long, (0.3–) 0.5–1.5 (–2) cm wide, oblanceolate to broadly obovate to broadly elliptic or even suborbicular, blades on short shoots (0.9–) 1.3–3.6 (–4.3) cm long, 0.2–

1.2 cm wide, mostly oblanceolate to broadly obovate, occasionally suborbicular, gently involute to slightly V-infolded along midvein, coriaceous, the apex rounded, occasionally acute or retuse, the base narrowly cuneate to acute, the margin entire and slightly revolute; venation conspicuously finely reticulate, the primary venation pinnate, the secondary venation brochidodromous, with secondary veins slightly decurrent, ascending, arcuate, branching off midvein in opposite to subopposite to alternate arrangement, ± in 3–8 irregularly spaced pairs, with an intersecondary vein occasionally

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occurring between secondaries, its length ca. 50% the length of the secondaries, its distal course reticulating, the tertiary veins irregular reticulate, the quaternary veins irregular reticulate to freely ramifying, areolation moderately developed, the marginal ultimate venation looped; adaxial leaf surface green, glossy, young leaves with widely and evenly scattered short, tightly curled, deciduous white trichomes, the vein reticulum conspicuously evident, veinlets flush to raised (fresh leaf), or mostly raised (dried leaf), giving the surface a textured, veiny appearance; abaxial surface with a very sparse but quite persistent loosely wooly indumentum of blonde to light brown T-shaped trichomes, the stalks 0.05–0.12 mm long, top portions 0.4–1.8 mm long, terete or flattened-twisted in cross-section, the top portions straight to curled, often kinked, ascending, the pubescence persistent throughout the growing season, surface occasionally glabrate on older leaves, the vein reticulum evident; stomata (Fig. 5-26) recessed inside dome-like, ellipsoidal chambers raised markedly from the leaf surface, each chamber opening wide and elliptical, sitting atop the dome, the guard cells visible through the opening, the dome encircled by one or more concentric cuticular ridges, at least one of these ridges forming a striking, neatly defined oval border around the dome, the surface between stomata patterned in strong relief, with cuticular ridges often radiating out from the stomatal complexes, epidermal cell boundaries often evident and marked by impressed grooves. Inflorescence a fascicle borne in a leaf axil, fascicles often clustered on short spur shoots in axils of fallen leaves, each fascicle having ca. 2–15 pedicellate flowers, the pedicels 1–4 (–7) mm long, glabrous. Calyx of 5 quincuncial, free sepals, the outer two sepals 1.7–2 mm long, 1.5–2.2 mm wide, ovate to suborbicular, the apex rounded, the margins entire, the inner three sepals 2–2.5 mm long, 2.1–3 mm wide, ovate to

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suborbicular, the apex rounded; the margin entire to erose, with a broad membranous rim, sepals glabrous, or with blonde pubescence basally and along midrib, outer sepals often with a sparse fringe of very short, dark red-brown T-shaped trichomes at the apex.

Corolla white, cyathiform, sympetalous, the tube 1.4–1.7 mm long, enclosed within the calyx; the lobes 5, exserted and spreading, glabrous, each with a median lobe and two lateral segments, the median lobe oval to orbicular, clawed, cupped around a stamen, the lateral segments 2–2.5 mm long (from junction with adjacent lateral segment), 1.5–2 mm long (from junction with median lobe), 0.7–1 mm wide, lanceolate, margins erose.

Stamens 5, epipetalous, opposite the corolla lobes, exserted; the filament 1.1–1.5 mm long, 0.3–0.4 mm wide, fixed at top of corolla tube, dilated proximally and narrowing toward anther attachment; the anther 1.1–1.3 mm long, 0.5 mm wide, sagittate, ventrifixed at the point of the sinus, opening by two dorsal longitudinal slits. Staminodes petaloid, alternating with stamens, each staminode 1.4–2 mm long, reaching no more than 2/3 the length of the median corolla lobe, 0.7–1.7 mm wide, deltoid to ovate, infolded, margin erose, translucent. Ovary superior, 5–(6 –) loculate, locules uniovulate with basal-axile placentation, ovary 1–1.1 mm long, 1–1.2 mm wide, subglobose, tapering abruptly to the style, top half glabrous, but pubescent basally with sparse to moderately dense indumentum of long, straight, appressed trichomes, style 1–1.5 mm long, glabrous, included. Fruit a berry, one (rarely 2)-seeded, 9–14.3 mm long, 8.5–13.3 mm wide, ellipsoid to subglobose, black, glossy, glabrous. Seeds 7–9.4 mm long, 5–7.6 mm wide, ellipsoid, the testa hard, smooth, glossy, uniform solid brown in color, the hilum scar basal, usually bipartite, the larger part basal, ± half-moon or heel-shaped,

1.6–2.2 mm long, 2.1–3 mm wide, the smaller part abaxial to the other part, roughly V-

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shaped or heart-shaped, 0.5–1.4 mm long, 1.2–2 mm wide, the parts well-separated by a bridge of testa, the scar being the exposed portion of a hollow cavity under the testa extending a small distance around the basal end of the seed, the cavity filled, especially on the abaxial side, with a yellowish fatty substance. (See Fig. 5-29).

Phenology. Flowering May through July, sometimes sporadically through

September. Fruit ripening August through October.

Common names. Big-fruited buckthorn; Ohoopee bumelia, Ohoopee bully.

Distribution and habitat. Sideroxylon macrocarpum is endemic to 13 counties in southeastern Georgia, mostly in the vicinity of the Altamaha River (Fig. 5-30). It is found in sandy, well-drained, pyrogenic, dry to mesic oak-pine woodlands. Sideroxylon macrocarpum’s growth habit, with most of its woody biomass below the soil or leaf litter surface, is no doubt an adaptation to periodic fires. Interestingly, S. macrocarpum also seems to thrive along powerline rights-of-way and road shoulders, where regular mowing (instead of fire) apparently favors the low-growing plant over its taller competitors (Allison 2006).

Conservation status. Listed as rare by the Georgia Department of Natural

Resources (Chafin 2008). The longleaf pine sandhill habitat of the southeastern USA comprises less than 3% of its original range (Condon & Putz 2007; Landers et al. 1995).

Threats to this habitat, and therefore to Sideroxylon macrocarpum, are from fire suppression and conversion of the habitat to pine plantations, pastures and other human development (Chafin 2008).

Illustrations. Chafin (2008, by J.C. Putnam).

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Specimens examined. USA. Georgia. Appling Co.: Ca. 12.8 air mi NE of

Baxley, NE side of Lamb Rd. (Co. Rd. 368), where it makes a 90° bend, ca. 0.6 air mi

SE of Woods Cemetery, 25 Jul 1996, Allison 9352 (FSU). Candler Co.: Ca. 7.9 linear mi WSW of Metter, N side of GA Hwy 46, ca. 0.2 rd. mi W of milepost 2, ca. 1.75 rd. mi

W of jct GA Hwy 57, 29 May 1996, Allison 9203 (GA). Emanuel Co.: Ca. 20 air mi S of

Swainsboro, ca. 3.7 air mi S of Oak Park, E side of Hwy 1, ca. 0.25 mi S of milepost 1, ca. 0.3 rd. mi S of jct Wiggins Rd. (Co. Rd. 248), ca. 4.1 rd. mi S of jct GA Hwy 86, 29

May 1996, Allison 9202 (FSU). Evans Co.: NW of Bellville, powerline running E-W about 1 mile N of GA 292, 16 Sep 2001, Allison 13043 (GA); ca. 5.6 linear mi W of

Claxton, ca. 1.8 mi NW of Bellville, intersection of powerline rights-of-way, just E of

Tattnall Co. line, 11 Sep 2005, Allison 13796 (GA); ibid., 32°10’04.1”N, 081°59’54.1”W,

30 Oct 2012, Corogin 1242 (FLAS). Jeff Davis Co.: Bullard Creek Wildlife Mgmt Area,

31°56’18”N, 082°25’59.8”W, 29 Oct 2012, Corogin 1235 (FLAS); open interior portion of powerline right-of-way, immediately W of Appling Co. line and 0.6 mi from Perry Miller

Rd., 31°52.85'N, 82°26.75'W, 26 May 1999, Nelson 20576 (GA). Laurens Co.: Ca. 19.2 air mi SE of Dublin, ca.9.2 air mi ENE of Cedar Grove. W side of Hwy 19, ca. 0.3 rd. mi

N of Wheeler Co. line and ca. 1 rd. mi S of Buck Cr., 21 Aug 1996, Allison 9404 (FSU,

USCH). Long Co.: Ca. 16.8 mi NW of Ludowici, roughly 7 mi E of Glennville (Tattnall

Co.), Fort Stewart Military Reservation, N of GA Hwy 144, 9 Jun 1997, Allison 9876

(FSU). Montgomery Co.: Ca. 9.9 linear mi SE of Mount Vernon, ca. 1 linear mi SW of

Alston, both sides of GA Hwy 135, ca. 2.5 rd. mi N of jct US Hwy 221 (Uvalda), at and just N of milepost 8, 22 Aug 1996, Allison 9411 (GA). Pierce Co.: Ca. 2 linear mi NE of

Blackshear, to N of Shiloh Church, 29 Sep 1999, Allison 12228 (GA). Tattnall Co.: Ca.

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1.7 air mi. NNW of Reidsville, E side GA Hwys 23/121/57, ca. 0.15 mi N of milepost 23, ca. 0.7 rd. mi N of jct Woodlawn Terr., 1.6 rd. mi N of jct US Hwy 280, 30 May 1996,

Allison 9207 (FSU, USCH); Gordonia Altamaha State Park, edge of woods by picnic area, 32°05’10.1”N, 082°07’44.1”W, 24 Sep 2012, Corogin 1184 (FLAS); Evans Tract,

NW of Brazells Creek, adjacent to Gordonia-Altamaha State Park, just E of US 280 about 1 mi N of crossing on Brazell’s Creek west of Reidsville, 14 Jul 2000, Govus 1193

(GA); sandhills of Ohoopee River near Reidsville, 24 Jun 1903, Harper 1851 (A, GH,

US). Toombs Co.: Ca. 5.2 linear mi WSW of Lyons, within city limits of Vidalia, E side of GA Hwy 15, immediately N of jct Barkdale Dr., ca. 1.6 rd. mi S of jct US Hwy 280

(Vidalia), 23 Aug 1996, Allison 9418 (GA); 0.5 mi E of Weyerhauser Rd, S side of US

280, E of Lyons, 32°08’24.4”N, 082°14’34.3”W, 30 Oct 2012, Corogin 1243 (FLAS).

Treutlen Co.: Ca. 7.7 air mi ENE of Soperton, E of Co. Rd. 167, ca. 0.6 mi S of jct GA

Hwy 86, ca. 0.8 rd. mi N of crossing of Pendleton Creek, 29 May 1996, Allison 9199

(FSU). Wheeler Co.: Ca. 11.3 linear mi NNE of Alamo, S side Oconee River, roughly

0.25 mi E of GA Hwy 46, 4 Jul 1996, Snow s.n. (GA).

Discussion. Sometime around 1830 (Graustein 1967), in sandhills near the

Altamaha River in Georgia, Thomas Nuttall made a collection of a low-growing, large- fruited plant he thought related to Bumelia reclinata. From this specimen he described

Bumelia macrocarpa (Nuttall 1849). Gray (1878) reduced Bumelia macrocarpa to a variety of B. lanuginosa, adding “to be rediscovered”; later (1886), he reduced it further to synonymy under B. lanuginosa, perhaps due to a lack of additional collections.

Subsequent collections of this plant, in the first half of the 20th Century, were identified as B. reclinata or B. lanuginosa (Allison 2006), until Cronquist (1949) described Bumelia

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thornei, after which collections of the low-growing sandy upland plant were often identified as B. thornei. Sideroxylon thornei is a wetland plant, but Cronquist, in his protologue (1949), had mischaracterized its habitat as dry woods, and the confusion persisted until the 1990s, when Anderson (1996) and Allison (2000) made it clear that the low-growing plants of sandy uplands were something distinct from S. thornei, perhaps an undescribed species. Allison and Anderson (1998), in an abstract, informally proposed naming this taxon Sideroxylon duncanorum. But then Allison discovered a single sheet in the herbarium of the Academy of Natural Sciences, Philadelphia (PH) containing a fragment matching Nuttall’s description of Bumelia macrocarpa that was clearly the same taxon as these Georgia upland plants, with a label in Nuttall’s handwriting, leading Allison (2006) to make a new combination, Sideroxylon macrocarpum (Nutt.) J.R. Allison, selecting this fragment as the lectotype. This forgotten taxon was thus indeed rediscovered, just as Gray had surmised it might be.

Sideroxylon macrocarpum shares similarities of habit, habitat and morphology with S. rufohirtum, a Florida endemic present in sandy pyrogenic upland pine habitats of

15 counties of the north, central, and western peninsula. Because of their similarities,

Allison (2006) hypothesized that S. macrocarpum and S. rufohirtum may be sister species, a supposition supported by morphological phylogenetic analysis (Chapter 3).

He also proposed a possible coevolutionary relationship between both plant species and the gopher tortoise, Gopherus polyphemus, an important seed-dispersing animal in pyrogenic sandy upland communities of the southeastern coastal plain (Auffenberg &

Franz 1982; Diemer 1986). Their low stature and clonal habit are also probably an adaptation to the periodic fires that occur in their habitats, and the similarities could also

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be due to convergent evolution. Although Sideroxylon macrocarpum and S. rufohirtum share many similarities, scanning electron microscope (SEM) examination of abaxial leaf surfaces reveals that the stomatal structures of S. macrocarpum, compared with those of the other southeastern U.S. Sideroxylon taxa, are unique and peculiar to the species. Stomatal structures of Sideroxylon rufohirtum are quite different from those of

S. macrocarpum, looking rather more like those of S. tenax, a plant associated with

Atlantic coastal beach dunes from Florida into the Carolinas, as well as inland Florida scrubs on former beach dunes. Sideroxylon tenax, unlike S. macrocarpum and S. rufohirtum, has a dense sericeous leaf indumentum, can reach considerable tree-size, and is not generally highly clonal.

For additional in-depth details of the taxonomic history and biology of S. macrocarpum, see the excellent discussion by Allison (2006).

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Figure 5-1. Distribution of Sideroxylon sect. Frigoricola.

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Figure 5-2. SEM images of abaxial leaf surface of four individuals of Sideroxylon lycioides. A) West Feliciana Parish, LA (Curry 341, LSU). B) Crittenden Co., KY (Browne 69E11.7, TENN). C) Perry Co., TN (Browne T-27, TENN). D) James City Co., VA (Ware 7860, FLAS). Magnification 1000×.

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Figure 5-3. Sideroxylon lycioides. A) Flowering branch. B) Fruiting branch.

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Figure 5-4. Distribution of Sideroxylon lycioides.

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Figure 5-5. SEM images of abaxial leaf surface of two individuals of Sideroxylon thornei. A) Liberty Co., GA (Corogin 1263, FLAS). B) Baker Co., GA (Allison 9369, FLAS). Magnification 1000×.

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Figure 5-6. Sideroxylon thornei. A) Leaf, adaxial (left) and abaxial views (dried specimens). B) Abaxial leaf surfaces, showing loose wooly indumentum. C) Branch. D) Leafy twigs, showing adaxial leaf surfaces. E) Inflorescence (dried specimen). F) Leafy twig on older branch. G) Small tree (center foreground), ca. 6 m tall, in bottomland hardwood forest, Liberty County, Georgia. H) Leafy twigs, showing abaxial leaf surfaces. I) Vegetative buds at tip of young long shoot (dried specimen). J) T-shaped trichomes typical of abaxial leaf surface, i.e., curled and ascending. K) Base of trunk of small tree, showing recent damage from larvae of the Bumelia borer beetle, Plinthocoelium suaveolens. Photos by the author.

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Figure 5-7. Distribution of Sideroxylon thornei.

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Figure 5-8. SEM images of abaxial leaf surface of Sideroxylon tenax. A) Corogin 1195 (FLAS), Brevard Co., FL. B) Corogin 1252 (FLAS), Marion Co., FL. C) Judd 3383 (FLAS), Highlands Co., FL. D) Corogin 1285 (FLAS), Polk Co., FL. Magnification 700×.

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Figure 5-9. Sideroxylon tenax. A) Flowering branch. B) Foliage, coastal dunes, St. Johns County, Florida. C) Shrub, ca. 2.5 m tall, in rosemary scrub, Highlands County, Florida. D) Fruiting branch (an elongated thorn), inland scrub, Lake County, Florida. E) Flowering twig. F) Tree, ca. 7 m tall, dunes on barrier island, Anastasia State Park, Florida. G) Ripening fruits and leaves clustered on brachyblasts. H) Flowering branches, inland scrub, Polk County, Florida. Photos by the author.

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Figure 5-10. Sideroxylon tenax, morphological examples typical of species of Sideroxylon sect. Frigoricola. A) Ripe fruits. B) Ripe fruit with seed, sectioned. C) Seeds. D) Young shoot sprouting from brachyblasts. E) Branching pattern. F) Flowering twig: inflorescences and leaves clustered on brachyblasts. G) Axillary bud on young long shoot. H) Leaf venation. I ) Trunk of mature shrub. J) Portion of long shoot, abaxial and adaxial views. K) Typical leaf of S. tenax, abaxial view: coastal variant (bottom) and inland Florida scrub variant (top). L) Abaxial leaf pubescence of S. tenax. M–N) T-shaped trichomes: terete (top), and flattened (bottom). Photos by the author.

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Figure 5-11. Sideroxylon tenax, flower, typical of species of Sideroxylon sect. Frigoricola. A–B) Corolla, inside view: rehydrated herbarium specimen (left), fresh specimen (right). C–D) Corolla, outside view: rehydrated herbarium specimen (left), fresh specimen (right). E) Whole flower. F) Anther, showing filament attachment. G) Ovary. Photos by the author.

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Figure 5-12. Distribution of Sideroxylon tenax.

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Figure 5-13. Sideroxylon tenax complex. A) view from above. B) view from below. From left: S. alachuense, with silvery leaf pubescence and light-colored twig; S. tenax, the Atlantic coastal variant; S. tenax, the interior Florida sand ridge (“lacuum”) variant, with darker-colored and less lustrous leaf pubescence. Photos by the author.

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Figure 5-14. SEM images of abaxial leaf surface of Sideroxylon alachuense. A) Corogin 1149 (FLAS), Alachua Co., FL. B) Corogin 1028 (FLAS), Alachua Co., FL. Magnification 700×.

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Figure 5-15. Sideroxylon alachuense. A) Thorn-tipped flowering twig. B) Flowering twig. C) Fruiting branch. D) Fruit and leaves clustered on brachyblasts. E) Young long shoot, first season’s growth. F) Flowering branch. G) Flowering twig. H) Long shoot, second season. I) Foliage, contrasting upper and lower leaf surfaces. J) Thorn- tipped twig. K) Lichen and moss growth on older twig. L) Inflorescence. M) Small tree, ca. 6 m tall, at edge of calcareous hammock near Alachua Sink, Payne’s Prairie State Park, Alachua County, Florida. N) Flowering twig. Photos by the author.

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Figure 5-16. Distribution of Sideroxylon alachuense.

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Figure 5-17. SEM images of abaxial leaf surface of six individuals of Sideroxylon lanuginosum, representing the three subspecies. A) Subsp. lanuginosum, Alachua Co., FL (Corogin 1001, FLAS). B) Subsp. lanuginosum, Coosa Co., AL (Kral 60488, TENN). C) Subsp. lanuginosum, Pontotoc Co., OK (Folley PON0321, OKL). D) Subsp. albicans, Austin Co., TX (Smith 35, LSU). E) subsp. rigidum, Cochise Co., AZ (Hess & Tyznik 3260, OKL). F) Subsp. rigidum, Bexar Co., TX (Lievens s.n., LSU). Magnification 700×.

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Figure 5-18. Sideroxylon lanuginosum. A) Flowering twig. B) Shrub, ca. 4 m tall. C) Branch, showing abaxial leaf surfaces. Photos by the author.

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Figure 5-19. Distribution of Sideroxylon lanuginosum.

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Figure 5-20. Distribution of morphological variants of Sideroxylon lanuginosum, sensu Cronquist (1945).

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Figure 5-21. SEM images of abaxial leaf surface of four different individuals of Sideroxylon reclinatum subsp. reclinatum. A) Corogin 1060 (FLAS), Gilchrist County, FL. B) Godfrey 81312 (FLAS), Taylor County, FL. C) Correll 42244 (FTG), Monroe County, FL, at Pine Crest in Big Cypress National Preserve. D) Godfrey 81581 (FTG), Columbia County, FL. Note that epidermal cell outlines, if visible at all, are defined by raised ridges without the presence of an impressed groove (see arrows). Magnification 500×.

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Figure 5-22. SEM images of abaxial leaf surface of four different individuals of Sideroxylon reclinatum subsp. austrofloridense. A) Corogin 1055 (FNPS), Long Pine Key, Everglades National Park. B) Possley 67 (FTG), urban Miami-Dade County, FL, Larry & Penny Thompson Park. C) Bradley 1547 (FTG), Collier County, FL, near Monument Lake, Big Cypress National Preserve. D) V.I. Sullivan s.n. (FTG), Long Pine Key, Everglades National Park. Note that epidermal cell outlines are defined in all cases by an impressed groove or a ridge with an impressed groove within it (see arrows). Magnification 500×.

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Figure 5-23. Distribution of Sideroxylon reclinatum.

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Figure 5-24. Sideroxylon reclinatum. A–B) Ovary. A) Sideroxylon reclinatum subsp. reclinatum. B) S. reclinatum subsp. austrofloridense. C–D) Flowering twig. C) S. reclinatum subsp. reclinatum. D) S. reclinatum subsp. austrofloridense. E–H) S. reclinatum subsp. austrofloridense, Long Pine Key, Everglades National Park. E) Shrub in marl prairie, ca. 1.5m tall (pine rockland in background). F) Flowering branch. G) Fruiting branch. H) Older branch, ca. 3cm diameter, with leaves and flowers on brachyblasts. Photos by the author.

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Figure 5-25. Distribution of Sideroxylon reclinatum subsp. austrofloridense (circled dots) and S. reclinatum subsp. reclinatum (squares). The range of S. reclinatum subsp. austrofloridense is centered on the Miami rock ridge, with outliers historically as far south as Key Largo and Flamingo, and more recently as far west and north as Big Cypress National Preserve. Map shows vouchered occurrences only.

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Figure 5-26. Sideroxylon rufohirtum and S. macrocarpum: SEM images of abaxial leaf surface. A–B) Sideroxylon rufohirtum. A) Corogin 1000 (FLAS), Alachua Co., FL. B) Simons 239 (FLAS), Suwannee Co., FL. C–D) S. macrocarpum. C) Allison 9404 (USCH), Laurens Co., GA. D) Allison 12228 (GA), Pierce Co., GA. Magnification 700×.

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Figure 5-27. Sideroxylon rufohirtum. A) Young long shoot, first season. B) Flowering twig. C) Flower at anthesis, with two flowers just past anthesis. D) Fruiting shoot. E) Young shoot, second season (note persistent stem pubescence). F) Flowering branch. G) Ripe fruit, the greenish variant. H) Ripe fruit and seed. I) Clonal patches in fire-maintained Pinus palustris plantation, Suwannee County, Florida (shoots to 0.8 m tall). J) Leaves and flowers clustered on brachyblasts. K) Clonal patch in disturbed sandhill habitat, Alachua County, Florida (shoots less than 0.5 m tall). L) Thorny branch bearing ripe fruit. Photos by the author.

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Figure 5-28. Distribution of Sideroxylon rufohirtum.

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Figure 5-29. Sideroxylon macrocarpum. A) Fruiting twigs. B) Flowering twig. C) Inflorescence (dried specimen). D) Clonal patch, ca. 1 m square (foreground), in oak woodland, Jeff Davis County, Georgia, shoots less than 20 cm tall. E) Shoot, ca. 20 cm tall. F) Clonal patch, ca. 20 m × 6 m (foreground), in powerline right-of-way, Evans County, Georgia, shoots less than 0.5 m tall. G) Twig. H) Branch, ca. 20 cm long. I) Thorn lengthening into leafy branch. J) Leaf (dried specimens), abaxial view (left), adaxial view. K) Multi-branched shoot. Photos by the author.

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Figure 5-30. Distribution of Sideroxylon macrocarpum.

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CHAPTER 6 CONCLUSION

Sideroxylon (Sapotaceae) is a tropical genus of worldwide distribution, with some species ranging into zones of temperate climate. The subject of this monograph is a group of eight species occurring in temperate to warm-temperate North America. These eight species are Sideroxylon alachuense, S. lanuginosum, S. lycioides, S. macrocarpum, S. reclinatum, S. rufohirtum, S. tenax, and S. thornei. This group is of particular interest as it is endemic to an area encompassing the southeastern North

American Coastal Plain, an area recently recognized as a global hotspot of biodiversity and endemism. Morphologically, these eight species are distinguishable from their tropical congeners by having a combination of fascicled leaves, conspicuously reticulate tertiary venation, short styles, and seeds with a bipartite hilum scar. These possibly synapomorphic morphological features, along with results of recent molecular phylogenetic analyses, have suggested that these species may form a monophyletic group. The monophyly and species makeup of this group were tested by conducting a molecular phylogenetic analysis that included all of these eight species plus 17 selected tropical relatives, using nuclear ITS DNA sequence data (Chapter 2). The results support the monophyly of the group, and show that it is sister to a clade containing

Neotropical species of the Caribbean and Central America. I have here recognized the

North American clade as Sideroxylon section Frigoricola.

Relationships among the species in this group were investigated by carrying out a morphology-based cladistic analysis, as well as a molecular phylogenetic analysis using sequences of two non-coding chloroplast DNA regions (Chapter 3). The morphological analysis employed 25 variable characters, including micromorphological

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features of stomata and abaxial leaf cuticular surfaces, and generated a well-resolved phylogeny in which seven subclades are evident (Fig. 3-1). In this phylogeny, the group features a suite of putative morphological synapomorphies, further supporting the monophyly of the section. The molecular analysis of chloroplast DNA, however, yielded a phylogeny with a different topology, suggesting possible relationships within the group, that are not supported by the morphology-based phylogeny. Groupings in both the morphological and molecular analyses were not strongly supported by bootstrap analysis. The low proportion of potentially informative variable characters in the DNA dataset used in the present study leads me to have more confidence in the morphological phylogeny as an accurate representation of relationships among the species of Sideroxylon sect. Frigoricola. Future molecular studies focused at the population genetic level may prove useful for testing this morphology-based hypothesis.

Biogeographically, Sideroxylon section Frigoricola is a clade with evidently minimal molecular divergence among its species, but with marked morphological differentiation, thus it represents a geologically recent radiation of a tropical group into a zone of temperate climate. My observations suggest that these eight species have differentiated eco-geographically, many showing distinct habitat preferences that isolate them from the other closely-related species, and others being separated by geographic barriers. That this group is endemic to the southeastern North American Coastal Plain makes it of special interest. Many of the species of Sideroxylon section Frigoricola are narrow endemics in this hotspot of biodiversity and endemism, and thus comparing them with other southeastern North American endemics will deepen our understanding of evolutionary patterns in this region.

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This monograph concludes with a formal taxonomic revision of the species and subspecies of Sideroxylon section Frigoricola (Chapter 5). Further study of the genus

Sideroxylon, especially phylogenetic analyses of both morphology and molecular sequences, with more thorough taxon sampling, will build upon this and other studies, furthering our understanding of phylogenetic relationships and biogeography of these plants. Future studies using DNA sequences at the population genetic level will be useful in further elucidating relationships among the species and subspecies of

Sideroxylon section Frigoricola.

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BIOGRAPHICAL SKETCH

Paul Corogin earned a Bachelor of Science in biology from The Ohio State

University in 1983, and spent a number of years working in landscaping and massage therapy. In the spring of 2003, he earned a Bachelor of Science in botany from the

University of Florida. While working for the Department of Biology as a teaching assistant, he continued his studies at the University of Florida, earning a Master of

Science in botany in the spring of 2008, and a Doctor of Philosophy in botany in the summer of 2015.

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