TWO

Systematics of Grasses ()

PAUL M. PETERSON AND ROBERT J. SORENG

The grass family (Poaceae or Gramineae) is the fourth largest relationships among organisms) of the major tribes of flowering family in the world and contains about California grasses. 11,000 in 800 genera worldwide. Twenty-three gen- era contain 100 or more species or about half of all grass Morphology species, and almost half of the 800 genera are monotypic or diatypic, i.e., with only one or two species (Watson and The most important feature of grasses (Poaceae) is a one- Dallwitz 1992, 1999). seeded indéhiscent fruit (seed coat is fused with the ovary Over the last 150 years the grass flora of California has wall), known as a caryopsis or grain (see Figure 2.1; Peterson been the subject of considerable attention by botanists. 2003). The grain endosperm is rich in starch, although it can Bolander (1866) prepared the first comprehensive list, recog- contain protein and significant quantities of lipids. The nizing 112 grasses from California, of which 31 were intro- embryo is located on the basal portion of the caryopsis and ductions. Thurber (1880) mentions 175 grasses in California, contains high levels of protein, fats, and vitamins. The stems and Beetle (1947) enumerates 400 known species. It is inter- are referred to as culms, and the roots are fibrous and princi- esting to note that Crampton (1974) recognized 478 grasses pally adventitious or arising from lower portions of the in California, and of these, 175 were introduced and 156 were culms. Silica-bodies are a conspicuous component of the reported as annuals (we report 152 annuals here). epidermis and are stored in silica short-cells. Many grasses We recognize 524 grass species in 144 genera; of these, 233 have (underground stems) or stolons (horizontal (44.5%) species in 65 genera are introduced (see Appendix 1), aboveground branches) that allow for vegetative reproduc- and the remaining 291 (55.5%) species in 79 genera are native. tion in perennial grasses. Another important feature of Thirty-seven species are endemic to California. One hundred grasses is intercalary meristems; these allow growth well fifty-two grasses in California are annual; of these 101 are below the apex, typically near the base of the plant. The introduced and 51 are native. Obviously the grass flora has leaves are parallel-veined and two-ranked with the basal por- been altered by humans, especially over the last 300 years tion forming cylindrical sheaths and the upper portion since European settlement. The percentage of introduced referred to as a blade. A ligule, located on the upper surface grasses is perhaps higher in California than in any other at the junction of the blade and sheath, commonly consists state, simply because there are many different habitats (from of a flap of tissue or hairs but can be lacking. The primary 212 feet below sea level in Death Valley to 14,496 feet on top is referred to as a with one to many of Mount Whitney) available for colonization of weedy two-ranked inserted along the floral axis or rachilla. species. In addition, many annual species and genera of The lowest two bracts of each spikelet, inserted opposite Mediterranean origins have found suitable habitats in each other, are called glumes, above which, along the California (see D'Antonio et al.. Chapter 6). rachilla, are borne pairs of bracts termed florets. Each floret To understand the important adaptations within the consists of a lemma (lower ) and palea (upper bract). grasses, a firm grasp of the unique morphological features Within each pair of lemma and palea the highly reduced that define this family is needed. We start this chapter flowers can be found. Each grass flower usually consists of with an introduction to the morphology and ecology of two or three small scales at the base called lodicules, an grasses and then discuss the phylogeny (evolutionary ovary with a style and two plumose stigmas, and one to six

Floret Dorsal Ventral Caryopsis

Culm FIGURE 2.1. Diagnostic features of a grass ( californka): caryopsis, culm, floret, flower, and spikelet. Illustrated by Alice R. Tangerini.

(but more commonly three) with basifixed anthers in the grasses: C3-fixing CO2 by ribulose 1,5-biphosphate that contain single-pored, wind-dispersed pollen grains. (Calvin-Benson cycle, found in all vascular ), and Lodicules function to open the florets during flowering and C4-fixing of CO2, in which the initial product of photo- evidently represent reduced perianth (sepals and petals) seg- synthesis is not the C3 unit 3-phosphoglycerate but a unit ments. Since the morphological features are often cryptic, or with four C atoms (oxaloacetate). This is produced when occasionally lacking, identification to species is often very CO2 is bound to phosphoenolpyruvate to form four-carbon difficult and requires a trained specialist. molecules (oxaloacetate or malate) in the Hatch-Slack cyle. There are corresponding anatomical, physiological, phyto- geographical, and ecological differences between these two Ecology types. The C3 grasses are well adapted to temperate climates Specializations for open habitats and grazing tolerance, with winter precipitation, whereas C4 grasses are well suited highly reduced floral structure, and wind pollination in the to tropical environments with summer/fall precipitation. grasses have enabled the family to be extremely successful The evolution of C4 photosynthesis has allowed grasses to at planetwide radiation and colonization. One notable fea- outcompete other plants in warm, tropical and subtropical ture of grasses and other monocots is intercalary meristems environments by limiting oxidation (photorespiration) of that allow individual culms to resprout once they have been photosynthetic products (Ehleringer and Monson 1993). removed. Grasses are well adapted to open, marginal, and All of these features have led to the family's ability to frequently disturbed habitats and can be found on every occupy nearly one-quarter of the earth's land surface in continent, including Antarctica. Two major photosynthetic various climatic environments as the dominant component or carbon dioxide (CO2) assimilation pathways can be found of .

OVERVIEW Arundineae 2(2) bunchgrasses were common only on well-watered flood- • Thysanolaeneae 1(1) plains (Wester 1981). ^ L£ Paniceae 13(57) Andropogoneae 11(23) Phylogeny I• 1(9) Despite variation among grass species in inflorescence struc- "• I• Danthonieae 6(15) ture and vegetative morphology, the grass family was proba- I• Eragrostideae 2(12) bly characterized as a distinct entity in most early cultures. 24(64) Three hundred years before the Christian era, Theophrastus, ^•Zoysieae 4(18) a Greek scholar, recognized the grass family and began to Bambuseae 2(2) teach his students the concepts of plant morphology. The 1(3) first scientific subdivision of the family was made by Robert ^:Oryzeae 2(4) Brown (1814), who recognized two different spikelet types [• Stipeae 9(35) between subfamily and (Festucoideae). •• I• Meliceae 3(22) Bentham (1881) recognized 13 tribes grouped in the two major subfamilies. Hitchcock (1935) and Hitchcock and '• I• Brachypodieae 1(5) Chase (1951), in their treatments of the grasses of the United I• 49(184) States, recognized 14 tribes in these two major subfamilies. Bromeae 1(32) The two-subfamily classification was used by most agrostol- M: 10(45) ogists for almost 150 years until more modern syntheses were FIGURE 2.2. A hypothetical phylogeny of the grass tribes represented developed. in California based on Soreng et al. 2005. The first numeral indicates With the infusion of molecular data our present concept the number of genera within a tribe, and the numeral in parentheses and classification of the grasses is changing at a rapid rate. 0 indicates the number of species in California. In California we currently recognize eight subfamilies: Bambusoideae, Ehrhartoideae, Pooideae, , Danthonoideae, Aristidoideae, , and Pani- coideae (GPWG 2001; Soreng et al. 2005), and in these sub- A cladogram showing the relationships of the 17 tribes families we recognize 18 tribes and 44 subtribes (Table 1). A represented in California is given in Figure 2.2. All grasses in cladogram (see Figure 2.2) of these 18 tribes summarizes the BEP (Bambusoideae, Ehrhartoideae, and Pooideae) clade the most widely accepted concepts regarding the phyloge- (all descended from a single common ancestor) and the netic relationships among the tribes and subfamilies repre- Californian are C3, whereas all grasses in sented in California (GPWG 2001, Soreng and Davis 1998, the Aristidoideae and Chloridoideae are C4. The Panicoideae 2000). The tree is rooted between the PAGAD and BEP have C3, C4, and C3-C4 intermediates, although the major- clades. Three numerically small, tropical subfamilies of ity of the species in California are C4. grasses, not represented in California, diverge below this Historically, the biome has been maintained by root point. In the PAGAD clade, a clade containing Pani- a myriad of biotic, climatic, and edaphic effects. First, there coideae (Andropogoneae, Thysanolaeneae, and Paniceae) usually is a dry season in which grasses and adjacent forest and the Arundinoideae (Arundineae) is sister to a clade border dry out and become flammable (Axelrod 1985). containing the Chloridoideae (Cynodonteae, Eragrostideae, Repeated fires favor grasses over most tree and shrub species, and Zoysieae), Aristidoideae (Aristideae), and Dantho- since they very easily resprout from the base. Second, large nioideae (Danthonieae). In the BEP clade the Pooideae herbivorous mammals (e.g., bison and antelope) are instru- (Brachypodieae, Bromeae, Meliceae, Poeae, Stipeae, and mental at maintaining and further opening up grassland Triticeae) is sister to a clade of the Ehrhartoideae (Ehrharteae communities (Axelrod 1985). An often overlooked conse- and Oryzeae) and the Bambusoideae (Bambuseae). The BEP quence of grazing animals is their effect on soil compaction, clade corresponds, in part, to the old term "festucoid" which again favors -forming grasses over trees and grasses used by historical agrostologists. The three most shrubs. diverse subfamilies in California are the Pooideae with 323 The exact species composition of California's pre- (61.6%) species in 73 genera, the Chloridoideae with 94 agricultural grasslands is not very well documented. (17.9%) species in 30 genera, and the Panicoideae with 80 Wester (1981) and Holstein (2001) have presented well- (15.3%) species in 24 genera. documented accounts based on historical records and current ecological samples of relict vegetation in California. They Panicoideae found these grasslands to be spatially diverse with many different species of the annual or perennial habit. In the The Panicoideae are the least diverse of the three major sub- San Joaquín Valley, grasslands were apparently dominated families represented by the California grasses, and there are by annual species and xerophytic shrubs, and perennial no endemic Panicoideae within the state. This paucity of

SYSTEMATICS OF CALIFORNIA GRASSES TABLE 2.1 Classification of the Grasses Found in California

Subfamily Bambusoideae Subtribe Phalaridinae Anthoxanthum, Phalaris Tribe Bambuseae Subtribe Brizinae Subtribe Arundinariinae Pseudosasa Subtribe Agrostidinae Subtribe Shibataeniae , Ammophila, Bromidium, Phyllostachys Calatnagrostis, , , Podagrostis, Polypogon Subfamily Ehrhartoideae (synonym: ) Subtribe Puccinelliinae Puccinellia, Sderochloa Tribe Ehrharteae Subtribe Poinae Apera, Dissanthelium, Poa Tribe Oryzeae Subtribe Alopecurinae Subtribe Oryzinae , Beckmannia, Phleutn Leersia, Oryza Subtribe Holcinae Subtribe Zizaniinae Holcus Zizania Subtribe Airinae , Deschantpsia, Vahlodea, Subfamily Pooideae Subtribe Scribneriinae

Tribe Stipeae Scribneria Subtribe Stipinae Subtribe Loliinae Achnatherunt, Hesperostipa, , Nassella, Festuca, Leucopoa, Lolium, Schedonorus, Vulpia Piptatherum, Piptochaetiutn, Ptilagrostis, Subtribe Dactylidinae Dactylis, Lamarckia Subtribe Ampelodesminae Subtribe Cynosurinae Ampelodesmos Tribe Meliceae Subtribe Parapholinae , Mélica, Catapodium, Cutandia, Hainardia, ParaphoHs Tribe Brachypodieae Supertribe Triticoidae Brachypodium Tribe Bromeae Supertribe Poodae Brotnus Tribe Poeae Tribe Triticeae Subtribe Torreyochloinae Subtribe Hordeinae Amphibromus, Torreyochloa , Elytnus, Hordeutn, Leymtis, Subtribe Aveninae Pascopyrum, Pseudoroegneria, Sécale Arrhenatherum, , , Gaudinia, Subtribe Triticinae Graphephorutn, Koeleria, Lagurus, Rostraria, Aegilops, Taeniatherum, Thinopyrutn, Triticum Sphenopholis, Trisetum TABLE 2.1 (CONTINUED) Classification of the Grasses Found in California

Subfamily Panicoideae Subfamily Danthonioideae

Tribe Thysanolaeneae Tribe Danthonieae Thysanolaena Cortaderia, Daitthonia, Karroochloa, Rytidosperma, Tribe Paniceae Schismus, Tribolium Subtribe Cenchrinae Cenchrus, Pennisetum Subfamily Chloridoideae Subtribe Digitariinae Tribe Cynodonteae Digitaña Acrachne, Blepharidachne, Dactyloctenium, Subtribe Melinidinae Leptochloa, Scleropogon, Swallenia, Tridens , Melinis, Urochloa Subtribe Boutelouinae Subtribe Setariinae Bouteloua Setaria, Stenotaphrum Subtribe Chloridinae Subtribe Panicinae , , Eustachys Dichanthelhnn, Echinochloa, Panicum Subtribe Eleusiniae Subtribe Paspalinae Eleusine Axonopus, Paspalutn Subtribe Hilariinae Tribe Andropogoneae Hilaria (Pleuraphis) , Miscanthus, Saccharum (Erianthus) Subtribe Monanthochloinae Subtribe Sorghinae Distichlis, Monanthochloe Bothriochloa, Sorghum Subtribe Muhlenbergiinae Subtribe Andropogoninae Lycurus, , Schedonnardus , Schizachyriutn Subtribe Munroinae Subtribe Anthistiriinae Dasyochloa, Erioneuron, Munroa Heteropogon, Hyparrhenia, Themeda Subtribe Orcuttiinae Subtribe Tripsacinae Neostapfia, Orcuttia, Tuctoria Zea Tribe Eragrostideae Subtribe Cotteinae Subfamily Arundinoideae Enneapogon Subtribe Eragrostidinae Tribe Arundineae Eragrostis , Phragntites Tribe Zoysieae Subtribe Sporobolinae Subfamily Aristidoideae Crypsis, Spartina, Tribe Aristideae Subtribe Zoysiinae Aristida Zoysia

NOTE: Based on Soreng et al. 2005. Native taxa are bold, introduced taxa are ligtitface type. All genera are italicized. A is considered native if it includes one or more native species (see Appendix 1 for clarification of native versus introduced species). species diversity is likely a direct response to the climatic the central and southern Sierra highlands. Members patterns of the past and present, because Panicoideae grasses of the Stipeae are well adapted to the steppe vegetation in are best suited to warm and humid environments of tropical and the , where they are often dominant ele- and warm temperate zones. The in this subfamily ments. Nassella cemua, N. lepida, and JV. pulchra are sometimes usually have two glumes and two closely spaced florets; the dominant in parts of the California grasslands. lower floret is usually sterile, the upper floret without a rachilla extension. Meliceae The next tribe to diverge from the main lineage in the Pooideae Paniceae clade is Meliceae, also reported as having possible fossils in the The Paniceae in California contain 57 species in 13 genera Oligocène of (Thomasson 1987). The Meliceae and are the sister to the Andropogoneae (Figure 2.2). They are have closed sheaths and lemmas that are five- to 13-nerved; characterized by having two-flowered spikelets with mem- short, bushy stigmas; and short, truncate, fleshy lodicules. branous glumes, the lower floret staminate or reduced, mem- Mélica torreyana is an endemic from the northwestern region, branous, and the upper floret perfect and firm. Even though the Sierra Nevada, and central western California. Three other Panicum (10 spp. in California) and Paspalum (4 spp. in varieties of Mélica are also endemic: Mélica californica var. California) are large genera in the eastern United States and nevadensis Boyle from northwestern and central western especially in tropical America, they are very poorly repre- regions. Sierra Nevada foothills, western , sented in the western United States, where the climate is and the Tehachapi Mountains; M. geyeri var. aristulata J.T. generally dryer, especially in the warmer months. Howell from the San Francisco Bay Area; and M. stricta var. albicaulis Boyle from the western Transverse Ranges. The Andropogoneae endemics Pleumpogon californicus and P. hooverianus occur in marshy areas from northwestern California, Cascade Range The Andropogoneae are characterized by having fragile foothills, and north and central Sierra Nevada foothills; and of paired spikelets, where there is a sessile and a from the southern North Coast and northern Central Coast pedicellate spikelet with differing sexuality. Commonly the regions, respectively. pedicellate spikelets are staminate or reduced, and the sessile spikelets are usually perfect or pistillate. Within spikelets, Poaeae typically the glumes are firm, and the two florets have mem- branous bracts. The Andropogoneae in California contains The largest tribe, Poaeae (184 spp.), includes Poa with 23 species in 11 genera, most of which are uncommon in 34 species. Poa has diversified throughout temperate, boreal, California grasslands. and arctic regions around the world and occurs on islands of similar habitats in the tropics (Gillespie and Soreng 2005). The Poeae clade, equivalent to supertribe Poodae, is sandwiched Pooideae between the ancestral Brachypodieae, with only five intro- There are a few morphological synapomorphies (diagnostic duced species, and the sister supertribe Triticoidae, which characteristics) delineating the Pooideae. In this subfamily includes the Bromeae, with 32 species, and the Triticeae, with trends include parallel-sided subsidiary cells, nonvascular- 45 species. In California, Poa exhibits both high species diver- ized lodicules with a membranous margin, an epiblast with sity (34 spp., of these, 28 are native) and a high degree of no scutellar cleft, and the absence of microhairs. endemism, with eight species confined to the state (see Appendix 1). Poa is characterized as having rather small, mul- tiflowered spikelets; lemmas that are keeled, unawned, usually Stipeae five-nerved, commonly with weblike hairs from the dorsal In California the earliest diverging lineage in the Pooideae side of the callus, caryopses that are firm with lipid and a short clade (Figure 2.2) is the Stipeae. The Stipeae probably arose in hilum; lodicules that are broadly lanceolate, often with a lat- Laurasia (37-24 mybp) since a few fossil reports, e.g., Stipideum eral lobe; leaf sheaths closed above the base between 1/20 the and possibly Piptochaetium, are from the Oligocène in North entire length and the top; leaf blades that generally have two America (Thomasson 1987). Therefore, ancestors of this tribe rows of bulliform cells (one on either side of the midnerve, likely were able to colonize the North American and Eurasian these appearing like railroad tracks) and no additional rows of continents before they separated. The Stipeae are characterized bulliform cells; and blades commonly with naviculate (boat- as having one-flowered spikelets without rachilla extensions shaped) apices (Soreng 1993; in press a, b). The Poaeae and terete florets that are usually awned near or immediately endemics, Poa kecki, P. stebbinsii, and , have orig- below the apex and have a well developed, often sharply inated on "islands" of arctic habitat in the high Sierra Nevada pointed callus. The Stipeae include three endemics centered in between 1,800 and 4,000 meters. Poa atropurpúrea is known the Sierra Nevada: latiglume from the Transverse only from high-elevation meadows (1,500-2,000 meters) in Ranges and central and southern Sierra Nevada, A. stillmanii the Peninsular Ranges and the San Bernardino Mountains. Poa from the northern Sierra Nevada, and Ptilagmstis kingii from sierrae and P. tenerrima (known only from serpentine outcrops)

12 OVERVIEW occur in the Sierra Nevada canyons and foothills. Poa napensis the ovary, and simple starch grains (Wagnon 1952; Saarela is known only from mineralized soils around hot springs in and Peterson in press). This genus is widely distributed in the North Coast Ranges, P. kelloggii is known only from the temperate and mountainous regions of the Northern and North and Central Coast Redwood forests (not found in Southern Hemispheres, and several species are important ), P. douglasii is known only from the South Coast native forage grasses in California [B. ciliatus, B. richardsonii, sand dunes, and P. diabolii is known only from coastal soft B. suksdorfti] (Peterson et al. 2002). Endemics within California scrub over Edna shale in the South Coast. These species oí Poa include grandis and B. hallii from the southern Sierra belong to three subgenera and four sections. Poa kelloggii Nevada, Transverse and Peninsular ranges; and B. pseudolaevipes belongs to the earliest-diverging lineage in the genus. from the San Francisco Bay Area, Outer South Coast Ranges, Sylvestres, a subgenus that, so far as is known, is endemic and South Coast, Channel Islands, Western Transverse Ranges, and principally confined to rich forests of North America. Poa the Peninsular Ranges (Saarela and Peterson in press). All three napensis and P. tenerrinia belong to subgenus Stenopoa section of these species were included in Wagnon's (1952) Pacific Slope Secundae and are closely related to P. secunda, which is perhaps Group of Bromus section Bromopsis, where he mentions that the most common native grass across California, occurring in B. grandis and B. hallii perhaps share a common origin with a wide range of habitats from coast range low-elevation sites to B. orcuttianus. Bromus carinatus is a widespread native that high-elevation Sierra Nevada meadows and Great Basin grass- occurs in many habitats mostly below 3500 meters. lands. Poa keckii belongs to a complex of short-anthered species The genus Bromus contains 15 introduced species; many of of the western cordillera of North America (Beringia), placed these are invasive in California grasslands. Bromus diandrus in subgenus Stenopoa section Abbreviatae. Poa atropurpúrea, and B. hordeaceus are widespread and dominant or codomi- P. douglasii, and P. diaboli are members of the diclinous Poa sub- nant throughout coastal and valley grasslands (see D'Antonio genus Poa section Madropoa, which is centered in and mostly et al.. Chapter 6). Bromus tectorum and B. madritensis subsp. endemic to western North America. Several other species oí Poa rubens (L.) Husn. are more common in the California . section Madropoa are nearly confined to California; P. pipen, These four species of Bromus are listed by the California Inva- P. pringlei, and P. rhizomata extend into SW Oregon on serpen- sive Plant Council (Cal-lPC at http://www.cal-ipc.org) as inva- tine, volcanic, and peridotite substrates, respectively. sive pest plants of concern to wildland habitat. Other endemic species in the Poeae, subtribe Agrostidinae include Agrostis blasdalei, A. hooveri, ophitidis, Triticeae and C. foliosa, all from the North and South Coast Ranges, and Dissanthelium califomicum (subtribe Poinae), which was previ- The Triticeae (sister to the Bromeae), or wheat grass tribe, in ously thought to be extinct but was recently re-collected on California includes 45 species in 10 genera. The tribe is char- Santa Catalina Island. Scribneria bolanderi, the sole species of acterized by having a true spike inflorescence where all the subtribe Scribneriinae, is endemic to vernal pool habitats in the spikelets are sessile and aligned singly or in groups of two or California Floristic Province, although it also reaches Oregon. three along the central rachis; coriaceous glumes and lemmas; The generic relationship between Agrostis and Calamagrostis ovaries with densely hairy apices; and caryopses with simple is somewhat controversial since both are morphologically starch grains and long hilums. The evolutionary history of similar and have one-flowered spikelets. Species of Calam- this tribe is fairly well known since wheat (Triticum aestivum), agrostis have rachilla extensions (usually hairy), a callus with ( vulgäre), and rye (Sécale céréale) are members. hairs, and membranous to chartaceous lemmas, whereas The tribe is thought to have originated in Eurasia, possibly species of Agrostis do not have rachilla extensions, have a cal- during the Miocene, and then radiated to the New World lus that is usually glabrous, and have hyaline to membranous (Blattner 2006). Two species, californicus and lemmas (Peterson and Saarela in press). Current research on pacificus, are endemic to coastal California. The former species Dissanthelium indicates that species in this genus should be is known from the North and Central Coast . North subsumed within Poa (Gillespie and Soreng 2005; Refulio Coast Ranges, and San Francisco Bay Area, and the latter is Rodriguez, personal communication). Puccinellia howellii known from the North and Central Coast and the Channel (Puccinelliinae), another endemic, is known only from mineral Islands. Leymus condensatus is also a conspicuous associate springs in the YoUa BoUy Mountains and the Klamath Range. (culms 1.5-3.5 meters tall) of the and coastal sage scrub in California and , , and L. triticoides was perhaps historically dominant on heavier Bromeae soils in valleys and hillslopes of Central California (Gould The Bromeae are characterized as having closed sheaths, and Moran 1981; Holstein 2001). lemmas that are bifid or toothed with a subapical awn, hairy apically bilabiate appendages of the ovary, and simple starch Chloridoideae grains. In California, Bromus (Bromeae) consists of 32 species; of these, 17 are native. Bromus can be distinguished from The core species in this subfamily share two morphological other grasses by having connate leaf sheath margins, sub- synapomorphies. All exhibit "Kranz" or C4 leaf anatomy apically inserted awns, hairy apical bilabiate appendages of (except Eragrostis walteri Pilg. from South ) and most

SYSTEMATICS OF CALIFORNIA GRASSES 13 have chloridoid bicellular microhairs (broad, short terminal the exact timing and routes of migration to both North cell the same thickness as the basal cell) present on leaf sur- America and are unknown. faces (Peterson et al. in press). Other character trends in the The Muhlenbergiinae are characterized by having spikelets chloridoids include a base chromosome number of ;ii = 10 perfect, staminate, or sterile; occasionally with cleistogenes in (a pleisiomorphy or ancestral characteristic), embryos with the leaf sheaths; inflorescence paniculate of spicate main nonlinear hilums that are usually punctiform or small with branches or a single ; spikelet-bearing axis disarticulat- elongate mesocotyl internodes, and two fleshy, vascularized, ing (falling entire) or persistent; spikelets solitary, rarely paired truncate lodicules (GPWG 2001; Soreng and Davis 1998). or in triplets, occasionally secund; glumes awned or unawned; However, most of these character trends are seen in sister sub- lemmas three-nerved, awned or unawned; and a base chro- families: Aristidoideae, Arundinoideae, Danthonioideae, and mosome number of ;ii = 8-10 (Peterson 2000). The largest Panicoideae. genus, Muhlenbergia, has 18 species in California with a sin- The Eragrostideae is considered the earliest diverging tribal gle introduced species ßAuhlenbergia schreberi). Two species, lineage of the chloridoids and is sister to a clade that con- M. califomica and M. ¡onesii, are endemic to California, the for- tains the Zoysieae and the Cynodonteae (Figure 2.2). Char- mer occurring in the South Coast and Transverse Ranges and acter combinations in the Eragrostideae include spikelets the latter known only from the northern Sierra Nevada and the with many florets, lemmas with 3 to 13 nerves, and many Klamath and High Cascade ranges (Peterson 1993, in press). species adapted to xeric habitats. At this point we have no Seven species (Neostapfia colusana, Orcuttia inaequalis, clear idea as to the relationships among the seven Cyn- O. pilosa, O. tenais, O. visada, Tnctoria greenei, and T. mucronata) odonteae subtribes (see Table 1). However, we do have good oí the eight species in the Orcuttiinae are endemic to molecular support for maintaining the tribe Cynodonteae California. Unlike most Chloridoideae, which are adapted to and morphological support for all of the seven subtribes summer rains, these annual species are well adapted to win- (Peterson et al. in press). There are no definitive morpho- ter rains and summer . They occur in the western part logical characters that differentiate the Cynodonteae from of the state in vernal pools, an endangered habitat. This the Eragrostideae and/or Zoysieae; the Cynodonteae essen- subtribe is a unique lineage in the Cynodonteae and is exclu- tially includes most of the variation present in the entire sively restricted to the California biome [Orcuttia califomica subfamily. and Tuctoria fragilis (Swallen) J. Reeder extend into Baja The evolutionary history of the chloridoids as a whole is California, Mexico]. even more obscure. Thomasson's et al. (1986) identification of Kranz anatomy in a fossil from a Miocene Ogallala for- Introductions mation in is the first definitive record. Since more than half of the genera within the Chloridoideae reside in There are 43 introduced grass species currently included Africa and all larger tribes and subtribes, excluding Muhlen- in the Cal-lPC Invasive Plant Inventory (Cal-lPC), and 28 bergiinae, have centers of diversity in Africa, Hartley species in 20 genera do not share any native congeners and Slater (1960) concluded that the subfamily probably (species belonging to the same genus). Two of these genera, originated on the African continent (perhaps during the Brachypodium with five species and Ehrharta with three Oligocène) and spread from that region to other parts of the species, represent introduced tribes, the Brachypodieae and world. Ehrharteae. Strauss et al. (2006) compared three groups: introduced species that are harmful to California , native Cynodonteae species, and introduced species that cause relatively little The Boutelouinae, Hilariinae, Muhlenbergiinae, and Orcut- harm to California . They demonstrated that tinae are clearly North American subtribes, but how their the harmful introduced species are more distant phyloge- ancestor(s) arrived there is obscure. These subtribes probably netically from the native species than the benign intro- ultimately descended from a Laurasian ancestor, given the duced species are. This is an interesting conclusion, since distribution of Muhlenbergia, i.e., predominantly from the it implies that Darwin's naturalization hypothesis and the southwestern United States and northern Mexico, and also "the escape from natural enemies" hypothesis are valid; with six species in China (Peterson 2000; Peterson and Ortiz- species that are more distantly related to the native com- Diaz 1998; Peterson et al. in press; Wu and Peterson 2006). munity are more likely to become noxious invasive weeds Since the Chloridinae are most species-rich in South America, (Strauss et al. 2006). it seems likely that they originated in that continent and The following grasses are currently on the alert category spread northward, although we have no genetic evidence for (species that appear to be expanding their range or species this. It is very difficult to determine any directional signal showing signs of being invasive in some areas) published by from the Monanthochloinae and Munroinae, although these the Cal-lPC: Brachypodium sylvaticum, Ehrharta longiflora, two subtribes are slightly more species-rich in South America, Spartina altemiflora, S. anglica, S. densiflora, and Stipa capensis. suggesting a southern derivation. The Eragrostideae and Aegilops triuncialis, Ammophila arenaria. Arando donax, Ehrharta Zoysinae are more likely west Gondwanaland groups, although calycina, and Taeniatherum caput-medusae are reported on the

14 OVERVIEW Cal-IPC list as having a high rating (species that have severe Achnatherum coronatum (Thurb.) Barkworth ecological impacts, have moderate to high rates of dispersal, Achnatherum diegoense (Swallen) Barkworth and are widely distributed). Achnatherum hymenoides (Roem. & Schult.) Barkworth *Achnatherum latiglume (Swallen) Barkworth Achnatherum lemmonii (Vasey) Barkworth Evolution toward Specialization Achnatherum lettermanii (Vasey) Barkworth We can see several overarching patterns in the distribution Achnatherum nelsonii (Scribn.) Barkworth of native and endemic species. There were repeated special- Achnatherum nevadense (B.L. Johnson) Barkworth izations to narrowly distributed habitats or restricted Achnatherum occidentale (Thurb. ex S. Watson) edaphic or climate settings: (1) isolated wetlands, including Barkworth (a) vernal pools, mostly of the Central Valley and adjacent Achnatherum parishii (Vasey) Barkworth foothills (Orcuttiinae, Scribneria, Phalaris lemmonii, Pleumpogon Achnatherum pinetorum (M.E. Jones) Barkworth califomicus, Pucdnellia simplex [now introduced in ]), *Achnatherum stilltnanii (Bol.) Barkworth (b) saline springs {Pucdnellia howellii and the rare P. parishii, Achnatherum thurberianum (Piper) Barkworth which is sporadic across the southwestern states) and min- Achnatherum webberi (Thurb.) Barkworth eralized soils around springs (Poa napensis), (c) freshwater Aeradme racemosa (B. Heyne ex Roem. & Schult.) Ohwi wetlands and moist mountain meadows (Pleumpogon hoove- Aegilops cylindrica Host rianus, Poa atropurpúrea, P. stebbinsii, Ptilagrostis kingii); Aegilops geniculata Roth (2) sand dunes (Agrostis blasdalii, Calamagrostis bolanderi, Aegilops tauschii Coss. Leymus paaftcus, Poa douglasii, Swallenia alexandrae); 3) ultra- Aegilops triuncialis L. mafic substrates (Calamagrostis ophitidis, Poa piped, P. rhizomata, Agropyron cristatum (L.) Gaertn. P. tenerrima) and isolated shales (P. diaboli); (4) alpine and Agropyron desertorum (Fisch, ex Link) Schult. peaks (Alopecurus aequalis, A. geniculatus, Calamagrostis Agropyron fragile (Roth) P. Candargy muiriana, Cinna bolanderi. Festuca brachyphylla, Koeleria *Agrostis blasdalei Hitchc. macrantha, Poa glauca ssp. rupicola (Nash) W.A. Weber, Agrostis capillaris L. P. keckii, P. pringlei); (5) the California Floristic Province (Achan- Agrostis densiflora Vasey therum latiglume, A. stillmannii, A. diegoense, A. coronatum); Agrostis elliottiana Schult. (6) central and south coastal grasslands (Mélica imperfecta, Agrostis exarata Trin. Nassella cernua, N. lepida, N. pulchra, Aristida hamulosa, Agrostis gigantea Roth Leymus condensatus, Muhlenbergia microsperma, M. rigens); Agrostis hallii Vasey (7) southern coastal mountains/chaparral and forests Agrostis hendersonii Hitchc. (Achnatherum parishii, Elymus stebbinsii. Mélica frutescens, * Agrostis hooveri Swallen M. torreyana, Phalaris californica, P. lemmonii). Many of these Agrostis idahoensis Nash species of limited distribution have evolved from more wide- Agrostis microphylla Steud. spread congeners and belong to genera that are species-rich Agrostis oregonensis Vasey and well established in California. Agrostis pallens Trin. Agrostis scabra Willd. L. Appendix 1 : A List of the Grass Species Agrostis variabais Rydb. Known to Occur in California Aira caryophyllea L. Intraspecific categories are not included. Bolded names Aira elegantissima Schur are native, and those marked with an asterisk (*) are endemic. Aira praecox L. All other species are introduced and naturalized. This list Alopecurus aequalis Sobol. was prepared using the Catalogue of New World Grasses Alopecurus carolinianus Walter (Soreng et al. 2005), PLANTS (USDA, NRCS 2006), and the Alopecurus geniculatus L. Grass Manual on the Web (Barkworth et al. 2006). Also Alopecurus myosuroides Huds. consulted but not completely followed were The Grasses of L. California (Smith 2006), A Synthesis of the North American Alopecurus saccatus Vasey Flora (Kartesz and Meacham 2006), and the Jepson Online Ammophila arenaria (L.) Link Interchange for California floristics (JOl 2006). We have Ammophila breviligulata Fernald not done an extensive evaluation for all possible introduc- Ampelodesmos mauritanicus (Poir.) T. Durand & Schinz tions, since these are continually being added as reports are Amphibromus neesii Steud. published. Andropogon glomeratus (Walter) Britton, Sterns & Poggenb. Achnatherum altutn (Swallen) Hoge & Barkworth Andropogon virginicus L. Achnatherum aridum (M.E. Jones) Barkworth Anthoxanthum aristatum Boiss.

SYSTEMATICS OF CALIFORNIA GRASSES 15 Aitthoxanthutn nitens (Weber) Y. Schouten & Veldkamp Bromus hordeaceus L. Aitthoxanthutn occidentale (Buckley) Veldkamp Bromus inermis Leyss. Anthoxanthum odoratum L. Bromus japonicus Thunb. Apera interrupta (L.) P. Beauv. Bromus laevipes Shear Apera spica-venti (L.) P. Beauv. Bromus madritensis L. Aristida adscensionis L. Bromus tnarginatus Nees ex Steud. Aristida califomica Thurb. Bromus marítimus (Piper) Hitchc. Aristida dichotoma Michx. Vasey Aristida divaricata Humb. & Bonpl. ex Willd. Bromus polyanthus Scribn. ex Shear Aristida hamulosa Henrard Bromus porten (J.M. Coult.) Nash Aristida oligantha Michx. *Brotnus pseudolaevipes Wagnon Aristida purpurea Nutt. Bromus racemosus L. Aristida schiedeana Trin. & Rupr. Bromus ríchardsonii Link Aristida temipes Cav. Bromus secalinus L. Arrhenatherum elatius (L.) P. Beauv. ex J. Presl & C. Presl Bromus sitchensis Trin. Arundo donax L. Bromus sterilis L. Avena barbata Pott ex Link Bromus suksdorfii Vasey Avena fatua L. Bromus tectorum L. Avena occidentalis Durieu Bromus vulgarís (Hook.) Shear Avena sativa L. Calatnagrostis bolanderi Thurb. Avena sterilis L. Calamagrostis brewerí Thurb. Avena strigosa Schieb. Calatnagrostis canadensis (Michx.) P. Beauv. Axonopus fissifolius (Raddi) Kuhlm. * Calamagrostis foliosa Kearney Becktnannia syzigachne (Steud.) Fernald Calatnagrostis koeleríoides Vasey Blepharidachne kiitgli (S. Watson) Hack. Calamagrostis tnuiríana B.L. Wilson & Sami Gray Bothriochloa harhinodis (Lag.) Herter Calatnagrostis nutkaettsis (J. Presl) J. Presl ex Steud. Bothriochloa ischaemum (L.) Keng * Calamagrostis ophitidis (J.T. Howell) Nygren Bothriochloa laguroides (DC.) Herter Calatnagrostis purpurascens R. Br. Bouteloua aristldoides (Kunth) Griseb. Calatnagrostis rubescetts Buckley Bouteloua barbata Lag. Calamagrostis strícta (Timm) Koeler Bouteloua curtipendula (Michx.) Torr. Catapodium rigidum (L.) Dony Bouteloua eriopoda (Torr.) Torr. Cenchrus ciliaris L. Bouteloua gracilis (Kunth) Lag. ex Griffiths Cenchrus echinatus L. Bouteloua trífida Thurb. Cenchrus incertus M.A. Curtis Brachypodium distachyon (L.) P. Beauv. Cenchrus longispinus (Hack.) Fernald Brachypodium phoenicoides (L.) P. Beauv. ex Roem. & Schult. Kunth Brachypodium pinnatum (L.) P. Beauv. Chloris truncata R. Br. Brachypodium rupestre (Host) Roem. & Schult. Chlorís verticillata Nutt. Brachypodium sylvaticum (Huds.) P. Beauv. Chlorís virgata Sw. L. *Cinna bolanderí Scribn. Briza media L. (Trevir. ex Go|2pp.) Griseb. Briza minor L. Cortaderia jabata (Lemoine) Stapf Bromidium tandilense (Kuntze) Rugólo Cortaderia selloana (Schult. & Schult, f.) Asch. & Graebn. Bromus alopecuros Poir. Crypsis alopecuroides (Piller & Mitterp.) Schrad. Bromus arenarias Labill. Crypsis schoenoides (L.) Lam. Bromus arízonicus (Shear) Stebbins Crypsis vaginiflora (Forssk.) Opiz Bromus berteroanus Colla Cutandia memphitica (Spreng.) K. Rieht. Bromus briziformis Fisch. & C.A. Mey. Cynodon dactylon (L.) Pers. Bromus carínatus Hook. & Arn. Cynodon plectostachyus (K. Schum.) Pilg. Bromus catharticus Vahl Cynodon transvaalensis Burtt Davy Bromus cebadilla Steud. Cynosurus cristatus L. Bromus ciliatus L. Cynosurus echinatas L. Bromus commutatus Schrad. Dactylis glomerata L. Bromus diandrus Roth Dactyloctenium aegyptiam (L.) Willd. * (Shear) Hitchc. Danthonia califomica Bol. *Bromus hallii (Hitchc.) Saarela & P.M. Peterson Danthonia decumbens (L.) DC.

16 OVERVIEW Daitthonia intermedia Vasey Eustachys distichophylla (Lag.) Nees Dattthonia unispicata (Thurb.) Munro ex Macoun Festuca ammohia Pavlick Dasyochloa pulchella (Kunth) Willd. ex Rydb. Festuca arvemensis Auquier, Kergue|41en & Markgr.-Dann. Deschatnpsia cespitosa (L.) P. Beauv. Festuca brachyphylla Schult. & Schult, f. Deschampsia danthonioides (Trin.) Munro Festuca califomica Vasey Deschatnpsia elongata (Hook.) Munro Festuca elmeri Scribn. & Merr. Dichanthelium acutninatutn (Sw.) Gould & C.A. Clark Elmer Dichanthelium oligosanthes (Schult.) Gould Festuca minutiflora Rydb. Digitaria bicornis Festuca occidentalis Hook. Digitaria ciliañs (Retz.) Koeler Festuca roemeri (Pavlick) E.B. Alexeev Digitaria eriantha Steud. Festuca rubra L. Digitaria ischaemum (Schreb.) Schreb. ex Muhl. Festuca saximontana Rydb. Digitaria sanguinalis (L.) Scop. Festuca sororia Piper *Dissantheliunt califomicutn (Nutt.) Benth. Festuca subulata Trin. Distichlis spicata (L.) Greene Festuca subuliflora Scribn. Echinochloa colona (L.) Link Festuca trachyphylla (Hack.) Krajina Echinochloa crus-galli (L.) P. Beauv. Festuca viridula Vasey Echinochloa crus-pavonis (Kunth) Schult. Gastridium phleoides (Nees & Meyen) CE. Hubb. Echinochloa muricata (P. Beauv.) Fernald Gaudinia fragilis (L.) P. Beauv. Echinochloa oryzoides (Ard.) Fritsch Glyceria borealis (Nash) Batch. Echinochloa phyllopogon (Stapf) Stapf ex Kossenko Glyceria elata (Nash) M.E. Jones Ehrharta calycina Sm. Glyceria fluitans (L.) R. Br. Ehrharta erecta Lam. Glyceria grandis S. Watson Ehrharta longiflora Sm. Glyceria leptostachya Buckley Eleusine indica (L.) Gaertn. Glyceria occidentalis (Piper) J.C. Nelson Eleusine tristachya (Lam.) Lam. Glyceria striata (Lam.) Hitchc. Elymus arizonicus (Scribn. & J.G. Sm.) Gould Graphephorum wolfii (Vasey) Vasey ex Coult. *Elymus califomicus (Bol. ex Thurb.) Gould Hainardia cylindrica (Willd.) Greuter Elymus canadensis L. Hesperostipa comata (Trin. & Rupr.) Barkworth Elymus elymoides (Raf.) Swezey Heteropogon contortus (L.) P. Beauv. ex Roem. & Schult. Elymus glaucus Buckley Hilaria famesii (Torr.) Benth. Elymus lanceolatus (Scribn. & J.G. Sm.) Gould Hilaria mutica (Buckley) Benth. Elymus nmltisetus (J.G. Sm.) Burtt Davy Hilaria rigida (Thurb.) Benth. ex Scribn. Elynms repens (L.) Gould Holcus lanatus L. Elymus scrihneri (Vasey) M.E. Jones Holcus mollis L. Elymus sierrae Gould Hordeum arizonicum Covas *Elymus stebbinsii Gould Nevski (Link) Gould ex Shinners Hordeum bulbosum L. Enneapogon desvauxii P. Beauv. Hordeum depressant (Scribn. & J.G. Sm.) Rydb. Eragrostis barrelieri Daveau Hordeum intercedens Nevski Eragrostis cilianensis (All.) Vignolo ex Janch. L. Eragrostis curvula (Schrad.) Nees Hordeum marinum Huds. Eragrostis hypnoides (Lam.) Britton, Sterns & Poggenb. Hordeum murinum L. Eragrostis lehmanniana Nees Hordeum pusillum Nutt. Eragrostis lutescens Hordeum vulgäre L. Eragrostis mexicana (Hörnern.) Link Hyparrhenia hirta (L.) Stapf Eragrostis minor Host Imperata brevifolia Vasey Eragrostis pectinacea (Michx.) Nees Jarava brachychaeta (Godr.) Peñailillo Eragrostis pilosa (L.) P. Beauv. Jarava ichu Ruiz & Pav. Eragrostis superba Peyr. Jarava plumosa (Spreng.) S.W.L. Jacobs & J. Everett Eriochloa acuminata (J. Presl) Kunth Jarava speciosa (Trin. & Rupr.) Peñailillo Eriochloa aristata Vasey Karroochloa purpurea (L. f.) Conert & Türpe Eriochloa contracta Hitchc. Koeleria macrantha (Ledeb.) Schult. Eriochloa fatmensis (Höchst. & Steud.) Clayton Lachnagrostis filiformis (G. Forst.) Trin. Eriochloa villosa (Thunb.) Kunth Lagurus ovatus L. Erioneuron pilosum (Buckley) Nash Lamarckia áurea (L.) Moench

SYSTEMATICS OF CALIFORNIA GRASSES 17 Leersia oryzoides (L.) Sw. (Hitchc.) Barkworth Leptochloa dubia (Kunth) Nees Nassella tenuissima (Trin.) Barkworth Leptochloa fusca (L.) Kunth Nassella viridula (Trin.) Barkworth Leptochloa panicea (Retz.) Ohwi *Neostapfia colusana (Burtt Davy) Burtt Davy Leptochloa viscida (Scribn.) Beal Orcuttia californica Vasey Leucopoa kingii (S. Watson) W.A. Weber *Orcuttia inaequalis Hoover Leytnus cinereus (Scribn. & Merr.) A. Love *Orcuttia pilosa Hoover Leytnus condensatus (J. Presl) A. Love *Orcuttia tennis Hitchc. Leytnus mollis (Trin.) Pilg. *Orcuttia viscida (Hoover) Reeder * Leytnus pacificus (Gould) D.R. Dewey Oryza rufipogon Griff. Leytnus salittus (M.E. Jones) A. Love Oryza sativa L. Leytnus triticoides (Buckley) Pilg. Panicum alatutn Zuloaga & Morrone Loliuni multiflorum Lam. Panicum antidotale Retz. Loliuni perenne L. Panicum capillare L. LoIiuni rigidum Gaudin Panicum dichotomiflorum Michx. Loliuni temulentuni L. Panicum hilltnanii Chase (Nutt.) C. Reeder Panicum hirticaule J. Presl Megathyrsus maxima Qacq.) B.K. Simon & S.W.L. Jacobs Panicum miliaceum L. Mélica aristata Thurb. ex Bol. Panicum repens L. Mélica bulbosa Geyer ex Porter & Coult. Panicum rigidulum Bosc ex Nees Mélica californica Scribn. Panicum urvilleanutn Kunth Mélica frutescetts Scribn. Paraphons incurva (L.) CE. Hubb. Mélica fugax Bol. Paraphons strigosa (Dumort.) CE. Hubb. Mélica geyeri Munro Pascopyrutn stnithii (Rydb.) Barkworth & D.R. Dewey Mélica harfordii Bol. Paspalum dilatatuni Poir. Mélica imperfecta Trin. Paspahitn distichutn L. Mélica spectabilis Scribn. Paspalum notatum Flügge Mélica stricta Bol. Paspalum urvillei Steud. Mélica subulata (Griseb.) Scribn. Pennisetum clandestinum Höchst, ex Chiov. * Mélica torreyana Scribn. Pennisetum glaucum (L.) R. Br. Melinis repetís (Willd.) Zizka Pennisetum latifolium Spreng. Miscanthus sinensis Andersson Pennisetum macrourum Trin. Mottattthochloe littoralis Engelm. Pennisetum nervosum (Nees) Trin. Muhlenbergia anditia (Nutt.) Hitchc. Pennisetum purpureum Schumach. Muhlenbergia appressa C.O. Goodd. Pennisetum setaceum (Forssk.) Chiov. Muhlenbergia arsenei Hitchc. Pennisetum villosum R. Br. ex Fresen. Muhlenbergia asperifolia (Nees & Meyen ex Trin.) Phalaris augusta Nees ex Trin. Parodi Phalaris aquatica L. *Muhlenbergia californica Vasey Phalaris arutidinacea L. Muhlenbergia filifortnis (Thurb. ex S. Watson) Rydb. Phalaris brachystachys Link Muhlenbergia fragilis Swallen Phalaris californica Hook. & Arn. *Muhlenbergia jonesii (Vasey) Hitchc. Phalaris canariensis L. Muhlenbergia mexicatia (L.) Trin. Phalaris caroliniana Walter Muhlenbergia microsperma (DC.) Kunth Phalaris coerulescens Desf. Muhlenbergia minutissitna (Steud.) Swallen Phalaris letntnonii Vasey Muhlenbergia montana (Nutt.) Hitchc. Phalaris minor Retz. Muhlenbergia pauciflora Buckley Phalaris paradoxa L. Muhlenbergia porteri Scribn. ex Beal Phleutn alpitnnn L. Muhlenbergia richardsotiis (Trin.) Rydb. Phleum pratense L. Muhlenbergia rigens (Benth.) Hitchc. Phragmites australis (Cav.) Steud. Muhlenbergia schreberi J.R Gmel. Phyllostachys bambusoides Siebold & Zuce. Muhlenbergia utilis (Torr.) Hitchc. Phyllostachys nigra (Lodd. ex Lindl.) Munro Munroa squarrosa (Nutt.) Torr. Piptatherum exiguum (Thurb.) Dorn 'Nassella cernua (Stebbins & Love) Barkworth Piptatherum tnicratithutn (Trin. & Rupr.) Barkworth NasselUí lepida (Hitchc.) Barkworth Piptatherum miliaceum (L.) Goss. NasselUí tnanicata (E. Desv.) Barkworth Piptochaetium setosum (Trin.) Arechav.

OVERVIEW Piptochaetium stipoides (Trin. & Rupr.) Hack, ex Arechav. Puccinellia nuttalliana (Schult.) Hitchc. *Pleuropogon califomicus (Nees) Benth. ex Vasey Puccinellia parishii Hitchc. *Pleuropogon hooverianus (L.D. Benson) J.T. Howell Puccinellia pumila (Vasey) Hitchc. Pleuropogon refractus (A. Gray) Benth. Puccinellia simplex Scribn. Poa ahhreviata R. Br. Postrarla cristata (L.) Tzvelev Poa annua L. Rytidosperma biannulare (Zotov) Connor & Edgar *Poa atropurpúrea Scribn. Rytidosperma caespitosum (Gaudich.) Connor & Edgar Poa higelovii Vasey & Scribn. Rytidosperma penicillatum (Labill.) Connor & Edgar Poa bolanderi Vasey Rytidosperma racemosum (R. Br.) Connor & Edgar Poa bulbosa L. Rytidosperma richardsonii (Cashmore) Connor & Edgar Poa compressa L. Saccharum ravennae (L.) L. Poa confmis Vasey Schedonnardus paniculatus (Nutt.) Branner & Coville Poa cusickii Vasey Schedonorus arundinaceus (Schreb.) Dumort. * Soreng & D.J. Keil Schedonorus pratensis (Huds.) P. Beauv. Poa douglasii Nees Schismus arabicus Nees Poa fendleriana (Steud.) Vasey Schismus barbatus (L.) Thell. Poa glauca Vahl Schizachyriutn cirratutn (Hack.) Wooton & Standl. Poa howellii Vasey & Scribn. Schizachyriutn scopariutn (Michx.) Nash Poa infirma Kunth Sclerochloa dura (L.) P. Beauv. *Poa keckii Soreng Scleropogon brevifolius Phil. *Poa kelloggii Vasey Scribneria bolanderi (Thurb.) Hack. Poa leptocotna Trin. Sécale cércale L. Poa lettermanii Vasey Setaria faberi R.A.W. Herrm. Poa tnacrantha Vasey Setaria itálica (L.) P. Beauv. * Poa napensis Beetle Setaria parviflora (Poir.) Kerguélen Poa nemoralis L. Setaria pumila (Poir.) Roem. & Schult. Poa palustris L. Setaria sphacelata Poa piperi Hitchc. Setaría verticillata (L.) P. Beauv. Poa pratensis L. Setaria virídis (L.) P. Beauv. Poa pringlei Scribn. Sorghum bicolor (L.) Moench Poa rliizoniata Hitchc. Sorghum halepense (L.) Pers. Poa secunda J. Presl Spartina alterniflora Loisel. *Poa sierrae J.T. Howell Spartina anglica CE. Hubb. *Poa stebbinsii Soreng Spartina densiflora Brongn. *Poa tenerritna Scribn. Spartina foliosa Trin. Poa trivialis L. Spartina gracilis Trin. Poa unilateralis Scribn. ex Vasey Spartina patens (Aitón) Muhl. Poa wheeleri Vasey Sphenopholis obtusata (Michx.) Scribn. Podagrostis hutnilis (Vasey) Björkman Sporobolus airoides (Torr.) Torr. Podagrostis thurberiana (Hitchc.) Hultén Sporobolus contractus Hitchc. Polypogon australis Brongn. Sporobolus creber De Nardi Polypogon elongatus Kunth Sporobolus cryptandrus (Torr.) A. Gray Polypogon imberbis (Phil.) Johow Sporobolus flexuosus (Thurb. ex Vasey) Rydb. Polypogon interruptus Kunth Sporobolus indicus (L.) R. Br. Polypogon maritimus Willd. Sporobolus vaginiflorus (Torr, ex A. Gray) Alph. Wood Polypogon monspeliensis (L.) Desf. Sporobolus wrightii Munro ex Scribn. Polypogon viridis (Gouan) Breistr. Stenotaphrum secundatum (Walter) Kuntze (Pursh) A. Love Stipa capensis Thunb. Pseudosasa japónica (Siebold & Zuce, ex Steud.) Makino ex *Swallenia alexandrae (Swallen) Soderstr. & H.R Decker Nakai Taeniatherum caput-medusae (L.) Nevski *Ptilagrostis kingii (Bol.) Barkworth Themeda quadrívalvis (L.) Kuntze Puccinellia distans (Jacq.) Parí. Thinopyrum intermedium (Host) Barkworth & D.R. Dewey *Puccinellia howellii J.l. Davis Thinopyrum junceum (L.) A. Love Puccinellia lemmonii (Vasey) Scribn. Thinopyrum ponticum (Podp.) Barkworth & D.R. Dewey Puccinellia marítima (Huds.) Parí. Thinopyrum pycnanthum (Godr.) Barkworth Puccinellia nutkaensis (J. Presl) Fernald & Weath. Thysanolaena latifolia (Roxb. ex Hörnern.) Honda

SYSTEMATICS OF CALIFORNIA GRASSES 19 Torreyochloa erecta (Hitchc.) G.L. Church Urochloa arizonica (Scribn. & Merr.) Morrone & Zuloaga Torreyochloa pallida (Torr.) G.L. Church Urochloa texana (Buckley) R.D. Webster Tribolium obliterum (Hemsl.) Renvoize Vahlodea atropurpúrea (Wahlenb.) Fr. ex Hartm. Tridens flavus (L.) Hitchc. (Leers) Coss. Tridens muticus (Torr.) Nash Vulpia bromoides (L.) Gray Trisetutn cemuutn Trin. Vulpia tnicrostachys (Nutt.) Munro Trisetum flavescens (L.) P. Beauv. Vulpia myuros (L.) C.C. Gmel. Trisetutn spicatutn (L.) K. Rieht. Vulpia octoflora (Walter) Rydb. Triticum aestivum L. Zea mays L. *Tuctoria greenei (Vasey) Reeder Zizania palustris L. *Tuctoria mucronata (Crampton) Reeder Zoysia japónica Steud.

20 OVERVIEW California Grasslands

ECOLOGY AND MANAGEMENT

Edited by

MARK R. STROMBERG JEFFREY D. CORBIN CARLA M. D'ANTONIO

[P

UNIVERSITY OF CALIFORNIA PRESS Berkeley Los Angeles London University of California Press, one of the most distinguisfied univer- Library of Congress Cataloging-in-Publication Data sity presses in tire United States, enriches lives around the world by advancing scholarship in the humanities, social sciences, and natural California grasslands : ecology and management / Mark R. Stromberg, sciences. Its activities are supported by the UC Press Foundation and Jeffrey D. Corbin, Carla D'Antonio, by philanthropic contributions from individuals and institutions. For p. cm. more information, visit www.ucpress.edu. ISBN 978-0-520-25220-2 (cloth : alk.paper) 1. Grasslands•California. 2. Grassland ecology•California. University of California Press 3. Grasslands•California•Management. 1. Stromberg, Mark R., Berkeley and Los Angeles, California 1951- 11. Corbin, Jeffery D. 111. D'Antonio, Carla, 1956-

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