Boletín de la Sociedad Botánica de México 56: 69-76, 1995 DOI: 10.17129/botsci.1465

Bol. Soc. Bot. México 56: 69-76 ( 1995)

Systematics of : and molecular phylogeny

DA VID J. BOGLER

Department of Botany, The University ofTexas, Austin, 78713-7640

Abstract. The results of a systematic study in which Dasylirion was fully monographed are reported. Sixteen , including four new ones, were recognized. Data from chloroplast DNA restriction site analysis suggest that the species of Dasylirion in southern are basal in the , that parvif/ora is particularly el ose to both Dasylirion and , and that is closest to Beaucarnea. The phylogeny of Dasylirion and the Agavaceae sensu lato was studied by comparison of cpDNA restriction sites and ITS rDNA sequences. The results strongly indicate that Dasylirion, Noli11a , Beaucarnea, and Calibanus are a monophyletic group that is closer to Maia11themum, Polygonatum, Liriope, Dracaena and Sansevieria than to and . Hasta and are at the base of the branch leading to Yucca and Agave. The molecular data indica te that Yucca whipplei is more closely related to than to other species of Yucca, and thatAgave dasylirioides and A. striata in the «Group Striatae» are basal to the rest of Agave. The resemblance of Aloe and Xa11thorrhoea to the Agavaceae appears to be due to convergen! evolution. Key words : Dasylirion, molecular phylogeny, Mexico, Nolinaceae, Taxonomy. Resumen. Se realizó el estudio monografico del género Dasylirio11. En esta revisión se reconocen 16 especies, incluyendo cuatro especies nuevas. El análisis de sitios de restrición del DNA de los cloroplastos (cpDNA) indica que las especies de Dasylirio11 del sur de Mexico son basales dentro del género, que Nolina parviflora está muy cercana a Dasylirion y Beaucarnea, y que Calibanus esta próximo a Beaucarnea. Se estudiaron las filogenias de Dasylirion y de las Agaváceas mediante comparaciones del cpDNA y secuencias de la región ITS del rDNA. Los resultados indican claramente que Dasylirion, Nolina, Beaucamea y Calibanus se encuentran en un grupo que está más cercano a Maianthemum, Polygonatum, Liriope, Dracaena y Sansevieria que a Yucca y Agave. De la misma forma, Hasta y Camassia son basales a Yucca y Agave. Los datos moleculares indican que Yucca whipplei está mas cercana a Hesperaloe que al resto de las especies de Yucca, y que Agave dasylirioides y A. striata del «G rupo Striatae» son basales a las otras especies de Agave. La semejanza entre Aloe y Xanthorrhoea y las Agaváceas parecen deberse a la convergencia evolutiva. Palabras clave : Dasylirion, filogenia molecular, México, Nolinaceae, Taxonomía.

INTRODUCTION study ofthe phylogenetic relationships ofDasylirion and the Agavaceae sensu lato. Dasylirion is a genus of 16 species found in rocky, arid regions ofthe southwestern U.S.A. andMexico. It is dioecious TAXONOMIC HISTORY OF DASYL!R/ON and easily recognized by its dense rosettes of prickly Jeaves The original description of Dasylirion (Zuccarini, 1838) and long, narrow stalks. It is commonly known was based on an assortmentofleaf collections, garden specimens as « » and has been u sed forfood, fiber, and thedistillation and species now placed in other genera. The status ofDasylirion of an alcoholic beverage also known as sotol. There have was clarified as more collections became available for study been few detailed studies ofthe taxonomy of Dasylirion and (Zuccarini, 1840). Although there was at one time sorne consequently the identification of collections is often difficult. confusion about the status of Nolina and Beaucarnea (Hemsley, Although it is generally recognized that Dasylirion is closely 1884), the distinctive marginal prickles of Dasylirion related to Nolina, Beaucarnea and Calibanus, it is not clear have made it easy to distinguish. Early efforts to monograph how these are related to Yucca, Agave and other members of Dasylirion were made by Baker (1872, 1881) and Watson the Agavaceae. Our research has focused on the taxonomy (1879). Most of the early descriptions were based on only a of spec ies of Dasylirion and the phylogenetic relationships few specimens and sorne of the characters are now known to of the species and the genus. In this paper we present a be more variable than previously supposed. The most recent simplified overview ofourresults, the details will be published monograph of Dasylirion was made by Trelease (1911), who elsew here. The first part is a general discussion of th e genus recognized 15 species, including thesix species which Trelease with the results of a chloroplast DNA (cpDNA) restriction described. The genus has recently been monographed and the site study of the species of Dasylirion. The second part 16 species of Dasylirion, including four new ones, recognized presents the highlights of a cpDNA and ITS sequencing by Bogler (1994) are presented in Table l.

______Bogler DJ. 1995. Systematics of Dasylirion: Taxonomy and molecular phylogeny. Boletín de la Sociedad Botánica de México 56: 69-76. 70 DA VID J. BOGLER

TABLE 1. Species of Dasylirion and new co mbinations recognized by strongly papillate-roughened. The of sorne species Bogler (1994). ha ve a coat of wax, which gives the leaf a blue-green or white aspect. The margins are lined with a row of sharp, usually forward-pointingprickles. The prickles areoccasionally recurved D. serratifolium (Karwinski ex Schultes) Zuccarini or distinctively colored in sorne species. In a few species the D. lucidum Rose prickles are greatly reduced in size or absent. The tip ofthe leaf D. acrotriche (Schiede ex Schultes) Otto occasionally dies back and splits into a mass of fibers. var. parryanum (Trelease) Bogler Inflorescence. The inflorescence is a very distinctive var. occidentalis Bogler feature of Dasylirion. It is a narrow, compound, spike-like D. glaucophyllum Hooker panicle with an elongate, bracteate peduncle that ranges D. berla 11 . :,eri Watson from 1-6 m in length from base to tip. are borne in var. palaciosii (Rzedowski) Bogler contracted fascicles of finger-like racemes arranged along var. longistylum (MacBride) Bogler the axis. There is a gradual transition from the lea ves to the D. miquihuanensis Bogler sp. nov. bracts of the inflorescence anda gradual reduction in the size D. treleasei Bogler sp. nov. of the bracts up the stalk. In most species the bracts are well D. quadrangulatum Watson [=D. longissimum] separated and stramineous, but are occasionally densely D. simplex Trelease overlapping and green or reddish colored. The fascicles of D. gentryi Bogler sp. nov . flowers are borne in the axils of the large inflorescence D. durangense Trelease bracts. There is generally a more or less elongated central D. sereke Bogler sp. nov. axis with a number of si de branches. The number of branches D. wheeleri Watson ex Rothrock varies with the position on the fascicle on the inflorescence. D. cedrosanum Trelease In sorne species it is much branched while in others there is D. leiophyllum Engelmann ex Trelease a reduction to 3 or fewer branches. var. glaucum (I.M. Johnston) Bogler Flowers. The individual flowers are borne in congested D. texanum Scheele spirals along the branches of the fascicles. Each is borne in the axil of a small, membranous laciniate bract. Within this bract there may be one or two smaller bracts. The pistillate flowers are borne on a di stinctly jointed pedicel. The receptacle is generally very small. There are six separate, MORPHOLOGY OF DASYLIRION elliptical or obovate with weakly laciniate tips. The Habit. Ali species of Dasylirion are polycarpic tepals are usually green or purple in color. There are six perennials with rosettes of fibrous leaves from a short or reduced, nonfunctional opposite the tepals. The elongate caudex. Flowering is terminal, with the apical ovary is sharply 3-angled and has only one locule at maturity. meristem developing in to the inflorescence. Growth continues Although there are initially six ovul es, only one or rarely two sympodially from axillary buds near the apex. Branching of ovules mature into . There is a very short style with the rosette occurs if more than one axill ary bud becomes three weakly united stigma lobes. These stigma lobes form active. an open tube which closes shut after pollination takes place. Trunks. Most species of Dasylirion have a woody Variation in the pistillate flowers involves primarily size caudex that increases in length and width. In a few species differences in th e tepals, style and stigma lobes. the caudex does not seem to grow much abo ve ground leve!, The staminate flowers are borne on short, non-jointed while in sorne species it may grow in toan upright trunk 2 m pedicels and have a very short receptacle. There are six in height with a corky periderm. In most species, however, separate obovate tepals with weakly laci ni ate tips. The six the trunk is not very wide or strong, and in older the stamens have glabrous filaments with exserted, dorsifixed trunk tends to recline on the ground. The trunks are often and introrsely dehiscent anthers. There appears to be little supported and protected by a skirt of stiff, dead leaves. variation in the staminate flowers of Dasylirion. . The system is fibrous and spreading. The . The mature of Dasylirion is hard to roots have a very tough, sclerified endodermis su rrounded categorize. lt is often described as an indehi scent , by a thick cortex of parenchyma cells. Young plants ha ve 2- but because it has only one it has also been called a 3 large, fusiform roots that are apparently contractile. Older nutlet (Dahlgren et al., 1985). Since it al so has three wings plants have a densely spreading root system. it has been called a samara. There is substantial variation in Leaves. Leaf characters are very important in the overall size, not only between species but sometimes within classification of Dasylirion. The lea ves are very fibrous and them as well. The length and shape of the wing lo bes and the drought resistant. They are usually dilated at the base into a sty le notch ha ve been frequently used to di stinguish species wide «spoon,» which in sorne species is thickened and of Dasylirion.. The seeds are trigonous, turbinate and gold en functions in storage. The blade is held in varying degrees of brown. There is little variation in the seeds except with one erectness. The surface of the leaf ranges from smooth to species that has distinct lobed seeds. SYSTEMATICS OF DASYLIRION: TAXONOMY ANO MOLECULAR PHYLOGENY 71

. Insect Visitors. There are many insect visitors to well defined groups. There seems to be strong geographic Dasylirion (Bogler, 1994 ). The most common and abundant component to the distribution of restriction site mutations. insects, and the ones that are probably responsible for most The most interesting result of this study is a restriction site of thc pollination, are small, short-tongued bees in the that is shared by Nolina anda group of species of Dasylirion families Halictidae, Andrenidae and Colletidae. Most of from southem Mexico, D. serratifolium, D. lucidum and D. these bees are generalists and have been associated with a acrotriche. The cpDNA data indicate that this group is variety of other plants. Larger bees, such asApis and Bombus separate from and perhaps basal to the other species found are al so commonly found on Dasylirion, as well as a variety in northem Mexico and the U.S.A. These species typically of Syrphidae flies, Cleridae beetles, and Wasps. There is have no wax on their lea ves and have a distinctive «brushy» wood-boring beetle in the family Buprestidae which is often leaf tip. found on Dasylirion, and its larvae develop inside of the Severa! restriction site mutations support a clade inflorescence stalk. containing populations of D. wheeleri from Texas, , and two populations from . One of these populations we recognize as Dasylirion gentryi, which occurs in the Rio Mayo region and is recognized by its very CHLOROPLAST DNA RESTRICTION SITE large, rose colored fruits and glabrous leaves. Although D. V ARIA TION IN DASYLIRION durangense and D. cedrosanum have waxy leaves like D. Evolutionary relationships between the species of , they appearon separate clades. Dasylirion durangense are not well known. About the only reference to this problem shares a restriction site mutation with D. simplex, a dwarfish was made by Trelease (1911), who recognized two sections species with aclump-like habitand reduced flower fascicles . in his key. The larger section consists of ali the species with Dasylirion cedrosanum is the name given to a complex of flat Jeaves that have marginal prickles. The other section waxy-leaved populations from and . Both contains only one unusual species, D. longissimum, which the cpDNA and morphological evidence indicates that has an enlarged upright trunk, quadrangulately thickened hybridization of D. cedrosanum with surrounding species leaves and greatly reduced prickles. We have examined has occurred. speci es relationships using molecular techniques and the Another clade contains a complex of species from results of our chloroplast DNA (cpDNA) restriction site southwestern Texas and Coahuila. This group includes D. analysis provide sorne evidence for subgeneric relationships. leiophyllum, D. stewartii and D. stewartii var. glaucum Although it was not possible to resol ve ali the species using which ha ve recurved leaf prickles, and three populations of cpDNA because of the low amount of variation present, the Dasylirion with mixed prickle curvature and waxy leaves. resu lts correlate with sorne morphological characters and After careful examination of the h~rbarium material, it was pro vide a found ation for future studies. concluded that there was very little reason to separate D. Methods. A cpDNA restriction site analysis of 37 stewartii and D. heteracanthum from D. leiophyllum, and populations of Dasylil 'on and two species of Nolina was that the waxy lea ves of D. stewartii var. glaucum are probably undertaken to try to resolve subgeneric relationships. The the result of introgressive hybridization with nearby populations methods used in this study have been reported in Bogler and of D. cedrosanum to the south. There is sorne evidence that Simpson (1995). Populations for this study were selected D. leiophyllum and D. ti:xanum are closely related and from throughout the range of the genus and included ali the hybridize in west Texas. The population of D. texanum from known species. Total DNA extracts were prepared from near Austin, Texas, appears to b..: isolated in terms of cpDNA frozen, powdered leaf material using 2X CTAB buffer. The restriction sites. DNA was digested with 12 restriction enzymes, run on Severa! species from northeastern Mexico and the agarose gels to separate the fragments and transferred to Sierra Madre Oriental, D. berlandieri and D. longissimum nylon membranes. The cpDNA fragments were visualized appear to be related to sorne extent, but the cpDNA evidence by hybridi zation with 25 labeled tobacco cpDNA probes is rather weak. is a peculiar species followed by autoradiography (Bogler, 1994). with large upright trunks, quadrangulately thickened lea ves Results. In general the leve] ofrestriction si te variation lacking prickles and massive . Two populations within Dasylirion was low, which is not uncommon in of D. longissimum were included in this study, one from woody, long-lived plants. However, 24 variable sites were and the other from . However, these two found, 19 of which were synapomorphic. These data were populations are not united by any cpDNA synapomorphies, used to analyze phylogenetic relationships in Dasylirion and the one from Hidalgo has a unique mutation. It turns out using Hennig86 (Farris, 1988). Three trees were found with that there are actually two species represented here which a length of 29 steps, a Consistency Index of 0.82 and a differ in morphological characters and bloom at different Retention Index of 0.92. One of these trees is presented in times ofthe year. The new species, D. treleasei which occurs Figure 1. in San Luis Potosi and Hidalgo also has flatter, more prickly Discussion. Although the levels of cpDNA variation leaves andan inflorescence that is more like other species of in Dasylirion were low, there was enough to resol ve severa! Dasylirion. In our monograph we use the more clearly 72 DA VID J. BOGLER

N parviflora 662 Pue N lindheimeriana 803 Tex D lucidum 641 Pue ...-1-~-D lucidum 663 Pue D serratifolium 647 Oax D. acrotriche Complex D acrotriche 787 Aguase S. Mexico D acrotriche 520 Hid ...__ _, >-D sp 774 Lagos Ja/ D parryanum 792 S L P ~ ~~D berlandieri 606 N L D berlandieri 74 7 N L ...... D longissimum 550 Hid D texanum 802 Tex D wheeleri 758 N M D sp S Viejo Son D wheeleri 7 2 5 Ariz D. wheeleri Complex ~..+-D wheeleri 75 7 N M NW Mexico, Ariz. and N. M. D wheeleri 72 7 Tex D sp Alamas Son D berlandieri 733 Tam O palaciosii 624 S L P D. berlandieri ~ ~-D palaciosii 61 6 S L P D longissimum 736 Tam D. longissimum Complex D sp 745 Dr Arroyo N L East-central Mexico O simplex 70 1 Dur l 1--t..+-D durangense 705 Dur D durangense 6 75 Dur D leiophyllum 762 Tex t--t.-+-0 texanum 711 Te x O texanum 731 Tex O cedrosanum 6 13 Zac O cedrosanum 590 Zac O /eiophyllum 752 Te x D. cedrosanum O cedrosanum 681 Coah D. leiophyl/um Complex D palmen· 603 Coah North-central Mexico and Texas D ste wartii 691 Coah D heteracanthum 688 Coah D stewartii 692 Coah O stewartii glaucum Coah

F10 . 1. Onc of three most parsimonious trees ob tained fro m ana lys is of 24 cpDNA restriction siles in Dasylirion. Length 29 steps, Consistency lndcx 0.82, Retcnti on lnd ex 0.92. Black boxes indi cate non-homop lasious res tric ti on site mutations. white boxes are ho mopl asious. Youcher numbers and co ll ection localiti es fo llow taxon nam es. SYSTEMATICS OF DASYLIRION: TAXONOMY AND MOLECULAR PHYLOGENY 73

defined name D. quadrangulatum for the populations of D. close to the baccate-fruited Dracaena, which has often been longissimum in Tamaulipas and Nuevo Leon. associated wíthSansevieria. Other baccate taxa in theLiliaceae Although D. longissimum looks very different at first sensu lato íncludeMaianthemum, Polygonatum, Liriope and sight, its flowers and fruits are similar to the rest of the Asparagus. Based on the similarity of their karyotypes, genus. The presence of rudimentary prickles at the base of Hasta has sornetimes been considered near Yucca and Agave its lea ves suggest it e volved out of a flat-leaved ancestor that (Tahktajan, 1980). Other woody lilioid taxa such as Aloe and had prickles. The cpDNA indicates a connection between D. Xanthorrhoea have sometimes been considered close to the berlandieri and D . longissimum, possibly through an Dasylirion or the Agavaceae, but whether the woody habit intermediate taxon from near Miquihuana, Tamaulipas. This has arisen once in these taxa or severa! times is not at ali taxon, which we are calling D . miquihuanensis, is large and clear. Recently, sorne progress has made by the analysis of has very erect, prickly lea ves that are somewhat quadrately rbcL sequences in the Agavaceae and (Eguiarte thickened as in D. longissimum. Possible hybrids between et al., 1994). Their results indicate that there are severa! this taxon and D . berlandieri have been seen. Although D. major lineages in this group of taxa and provide support for berlandieri is distinct from other species in many respects, a narrow interpretation of the Agavaceae. We have found with its droopy leaves, club-shaped inflorescences, green additional support and resolution using cpDNA restriction bracts and very large fruits, the populations are not well si te analysis (Bogler and Simpson, 1995) and ITS rDNA resolved by the cpDNA data. There is at least sorne support sequencing (Bogler et al., in press). far a relationship between D. berlandieri and D. palaciosii, which are very similar and considered a single species.

CHLOROPLAST DNA RESTRICTION SITE V ARIA TION IN THE AGA V ACEAE GENERIC RELA TIONSHIPS OF DASYLIR!ON Methods. An anal y sis was made of chloroplastDNA (cpDNA) restriction site variation in 40 taxa in the Agavaceae sensu Severa! viewpoints concerning the phylogeny and family lato. Detailed procedures are presented in Bogler and Simpson classification ofDasylirion ha ve been advanced. Hutchinson (1995). Total DNA was extracted frorn frozen tissues using (1934) and Cronquist (l 981) favored a close relationship 2X CTAB buffer. TheDNAs weredigested with 12 restriction between Dasylirion, Nolina, Beaucarnea and Calibanus enzymes. The fragments were separated on agarose gels, with Agave and Yucca, and included ali these taxa in the transferred to nylon mernbranes and hybridized with 25 Agavaceae (Agavaceae se ns u lato). Other systematic treatments radioactively labeled probes rnade from known tobacco (Dahlgren et al., 1985) place Dasylirion and its allies in a cpDNA templates. Partial restriction siternaps wereconstructed separare family, the Nolinaceae, and restrict the Agavaceae from the autoradiograrns and 110 informative restriction to just Yucca and Agave and their closest allies (Agavaceae sites were selected for phylogenetic analysis with PAUP sensu stricto). The sitPation is somewhat confusing because (Swofford, 1993) and Hennig86 (Farris, l 988). both systems are in me at the present time. Results. Heuristic analysis with the characters treated The morphological evidence suggests that the closest as unordered resulted in 44 equally parsimonious trees of relatives ofDasylirion areBeaucarnea, Nolina and Calibanus. 170 steps, a Consistency I:idex of0.64 anda Retention Index These genera ali ha ve similar xeromorphic features, relatively small flowers and dry, often winged fruits with 1-3 light of 0.91. A consensus of thesr trees is presented in Figure 2. brown seeds. They are nearly ali dioecious and most have a Discussion. The resulL of this study provide strong chromosome numberof n= 19. They are pollinated mainly by additional evidence that there are two major clades in the a number of small bees. The Nolinaceae are usually placed Agavaceaesensulato. However, thecpDNA data al so indicate near Dracaena, which differs in having baccate fruits. Although that the lineage containing Dasylirion and Dracaena is Yucca and Agave might be considered to resemble th e much closer to the Convallariaceae than previously thought. Nolinaceae in having fibrous lea ves and often woody habit, In addition, the cpDNA data support the association of they differ in most other respects. Yucca, Agave, and their Hasta to Yucca andAgave, as thesirnilarity oftheir karyotypes allies generally ha ve large, fleshy, perfect flowers adapted suggests. This observation has implications for the family forpollination by a variety oflarge bees, moths, classification of the Agavaceae se ns u lato. Sin ce Dasylirion and bats. The fruits are mostly dehiscent, many seeded appears to be closerto genera such asliriope and M aianthemum, capsules. The seeds of Yucca and Agave are black and then it really is not appropiate to view Dasylirion as a strongly fl attened. The chromosome of these taxa is n=30, mernber of the Agavaceae in the sen se of Cronquist ( 1981 ). or multiples of 30 in sorne Agave. The karyotype of these Instead, the cpDNA supports th e view that Dasylirion, genera is very di stinctive, with 5 large chrornosomes and 25 Nolina, Beaucarnea and Calibanus should be considered in small ones (Granick, 1944). a family apart, the Nolinaceae sensu Dahlgren et al. (1985). A nurnber of other taxa in the Liliaceae sensu lato The bootstrap values for these lineages are very hi gh. have at vari ous times been placed near Dasylirion or Yucca The cpDNA data also indicate a number of other and Agave. Dasylirion and other Nolinaceae are considered interesting relationships. In the Nolinaceae, Beaucarnea 74 DAVID J. BOGLER

.-l\.ll~1il- Cordyline termina/is ~.fi.!1..[HHJ.!HH1-Hemerocallis fu/va

HHHr.-1H11Jr Hypoxis hirsuta

HHH1+1:HHt1HH111l'IM.i-Asparagus officinalis

Dracaena marginata Dracaenaceae n=19,20 Sansevieria trifasciata J 100 Aspidistra elatior Convallaria maja/is Con~a!lariaceae ] ~~uuu~Maianthemum racemosum n-10,18,19 ¡;¡ :r lll Nolina parviflora "$, CD o:::::¡ 3 a;· CD (/) ¡u o :J .., Beaucarnea purpusii ¡u(") ::is. Nolinaceae n=18, 19 2S: ro c5 ¡¡;

Nolina nelsonii Nolina lindheimeriana """'""'"'"'-Xanthorrhoea sp ] Xanthorrhoeaceae n= 11 ventricosa ] Funkiaceae n=30 Yucca whipplei Hesperaloe funifera Hesperaloe parviflora Yucca elata iJ :r '

F1G. 2. Stri ct conse nsus of 44 trees obtained from ana lysis of 11 Oc pDNA restriction si tes in the Agavaceae and rclated families. Length 170 steps, Co nsistency lnd ex 0.64, Retenti on Ind ex 0.9 1. Black boxes indicate non-homoplasious cpDN A restri ction site mutations, white boxes are homop las ious. Boo tstrap va lues from 100 rep li cations are shown below the branches. Family names follow Dahlgren et al. (1985). SYSTEMATICS OF DASYL!RION: TAXONOMY AND MOLECULAR PHYLOGENY 75

o Polianthes geminiflora Polianthes pringlei Prochnyanthes mexicana 1 Manfreda scabra 3 Manfreda virginica 3 Agave americana 8 4 100 Agave attenuata 55 Agave lechuguilla 4 Agave dasylirioides 13 11 Agavaceae 100 6 Agave striata o 2 a/biflora 3 Beschorneria yuccoides 18 Furcraea pubescens 99 Hesperaloe funifera Hesperaloe parvif/ora Yucca whipplei 29 Yucca elata 92 6 56 Yucca treculeana 25 Camassia scilloides Hyacinthaceae 15 J Hosta ventricosa J Funkiacae 42 Cordy/ine termina/is J Asteliaceae Dasylirion berlandieri Oasylirion longissimum 25 Dasylirion wheeleri 61 Beaucarnea purpusi Nolinaceae Beaucarnea recurvata Nolina líndheimeriana Nolína nelsonii 44 27 Nolína parviflora 74 98 Dracaena margina.ta D racae naceae Sansevíeria trífascíata J Liriope muscari 10 Maíanthemum racemosum Convallariaceae Aspidistra elatior ] Polygonatum bíflorum 75 Asparagus officínalis ] 65 Xanthorrhoea sp J Xanthorrhoeaceae 125 Aloe bainesíi J Asphodelaceae

F1 0. 3. Stri ct consensus of 4 lrees obtained by analysis of combin ed ITS 1 and ITS2 rD NA sequen ce data sets in the Agavaceae and re lated families. Leng th 979 stcps, Consislency lndex 0.659, Relenti on Jndex 0.8 15. The numbers above the branches are the number of shared base substitutions, th ose bclow th e branches are bootstrap valu es obtained from 100 repli cati ons. Fam il y names fo ll ow Dahlgren et al. (1 985). 76 DAVID J. BOGLER and Calibanus are evidently closely related to each other. and Convallariaceae. Our results strongly support a narrow Although Nolina is most likely basal to the other genera, it interpretation of the Agavaceae. appears that N. parviflora is more closely related to both Dasylirion and Beaucarnea. In the Agavaceae sensu stricto ACKNOWLEDGMENTS . 1 would like to thank the it appears that Yucca whipplei is more closely related to Institute of Latin American Studies at the University of Hesperaloe than it is to other species of Yu cca, aresult which Texas at Austin far partial travel support. Abisaí García• has implications for the interpretation of the pollination Mendoza at the Jardín Botánico del Instituto de Biología de biology of Yucca (Bogler et al., in press). Relatively low la UNAM and the staff of the Desert Botanical Garden levels of cpDNA variation were found within Agave and graciously provided leaf material. fon Bogler and Burford genera such as Manfreda, Polianthes and Prochnyanthes, Westlund assisted with the fieldwork. indicating that these genera are very closely related.

LITERA TURE CITED ITS RIBOSOMAL DNA SEQUENCE Baker JG. 1872. On Dasylirion and Beaucarn.ea. l ou rnal of Botany V ARIA TION IN THE AGA V ACEAE 10: 296-299, 323-329. Methods. Relationships between these taxa were further Baker JG. 1881. A synopsis of Aloineae and Yuccoideae. Journal of studied using ITS rDNA sequences. For the sequencing the Linnean Society, Botany 18: 148-241. study we in cluded the same taxa as the cpDNA study plus Bogler DJ.1994. Taxonomy and phylogeny of Dasylirion (Nolinaceae) . PhD thesis. Austin: The University of Texas. a few add itional outgroups. The intern al transcribed spacers Bogler DJ, Simpson BB. 1995. A chloroplast DNA study of the (ITS l and ITS2) of the 26S-5.8S-18S nuclear ribosomal Agavaceae. Systematic Botany 20: 19 1-205. DNA region were amplified by PCR, sequenced using a Bogler DJ, Neff JL, Simpson BB. In press. Multiple origins of th e direct, doubl e stranded technique and optimally aligned Yucca-yu cca moth association. Proceedings of the National using PILEUP in th e GCG (1994) package (Bogler, 1994; Acodemy of Sciences. USA: 92. · Bogler et al., in press). These sequences ha ve been deposited Cronquist A.1981. An integ rated system of classification offlowering in Gen Bank. The aligned sequences were analyzed using plants. New York: Columbia University Press. Dahlgren RM, Cli fford HT.1982. The : A comparative PAUP (Swofford , 1993). study. London: Academic Press. Results. Sequence length in the Agavaceae sen.su Dahlgren RM, Clifford HT, YEO PF. 1985. The families of th e stricto was about 250 bp in ITSl and 211-239 bp in ITS2 . monocotyledons. Berlin: Springer Ycrlag. The ITS l and ITS2 sequences were ali gned and the matrices Eguiarte LE, Duvall MR, Learn GH Jr., Clegg MT. 1994. The were analyzed with PAUP, both separately and combined systematic status of the Agavaceae an d Nolin aceae and related together. In general, the phylogenetic anal yses of ITS 1 and Asparagales in the monocotyledons: An analysis based on the ITS2 produced trees that were congruent in the major lineages rbcL gene sequence. Boletín de la Sociedad Botánica de fo und . Analysis of a combined data set results in 4 equally México 54: 35-56. parsimonious, well resolved trees with 979 steps and a Farris JS. 1988. Hennig 86. Program and docu.mentation. New York: Port Jefferson Station. Consistency Index of 0.659. A strict consensus of th ese 4 GCG. 1994. Program manual for the Wisconsin package, Version 8. trees is shown in Figure 3. Madi son, Wi sconsin: Genetics Computer Group . Discussion. The ITS sequence data strongly support Gentry HS. 1982. of Continental . Tucson: the existence of two major lineages, one with Dasylirion and University of Ari zona Press. it s ali ies in the No 1inaceae , Dracaenaceae and Con vallariaceae Granick E. 1944. A karyosystematic study of the genu s Agave. Ame· and the other with the Agavaceae sensu Dahlgren et al. rican Journ.al of Botony 31: 283-298. ( l 985). Nolina is at the base of the clade leadi ng to both Hemsley WB. 1884. Biologia Centrali-Americana 3: 37 1-374. Dasylirion and Beaucarnea, which is is closely related to Hutchinson J. 1934. The families of flowering plants, Vol. JI. Monocotyledons. Oxford: Clarend on Press. Calibanus. One interesting result was that Camassia appears Swofford DL. 1993. PAUP: phylogenetic analysis using pa rsimony, to be closely related to Yucca and the Agavaceae sensu version 3. J. 1. Champaign: Illinois Natural History Survey. stricto. The sequence data also indicates a clase relationship Takhtajan A. 1980. Outline of th e classifi cation of flowering plants between Yucca whipplei and Hesperaloe. It appears that (Magnoliophyta). Botanical Review 46: 225-359. Agave dasylirioides and A. striata in the Gro up Striatae, Trelease W. 1911. The desert group Nolineae. Proceedings of the which was thought to be primitive in the genus by Gentry American Philosophical Society SO: 404-442. (1982), are indeed on a separate and basal lineage from the Watson S.1879. Revision oftheNorth American Liliaceae. Proceedings other species of Agave exam ined here. The ITS sequence of the American Acodemy Arts and Sciences 14: 213-289. Zuccarini JG. 1838. Ueber eine neue Gattun g aus der Famili e der data indi cate that Cordyline, Aloe and Xanthorrhoea are not Bromeli aceae. Allgemeine Gartenzeitung 33: 257-259. closely related to the Agavaceae. Zuccarini JG. 1840. Plantarum novarum ve! minus cognitarum, qu ac From these phy logenetic studies we conclude that in horto botanico herbarioque regio monacensi servantur, fasc iculus Dasylirion and related genera in the Nolinaceae belong to a qumtus. Abhandlungen der Mathematisch-Physikalischen Classe lineage that is distinct from Yucca and Agave. The lineage der Ki:i ni gli ch. Ba ye ri schen Akademie Wissenschaften 3, Abt. which contains the Nolinaceae also includes the Dracaenaceae 1: 220-229.