Phylogenetic relationships of Scaphyglottis and related genera (Laeliinae: Orchidaceae) based on nrDNA ITS sequence data ROBERT L. DRESSLER, W. MARK WHITTEN, NORRIS H. WILLIAMS AND Dressler, R. L. (Florida Museum of Natural History, Missouri Botanical Garden, and Marie Selby Botanical Garden; mailing address: 21305 NW 86th Ave., Micanopy, FL 32667; email: rdressl@nersp.nerdc.ufl.edu), W. M. Whitten & N. H. Williams (Florida Museum of Natural History, University of Florida, P.O. Box 117800, Gainesville, FL 32611-7800; email for Whitten: whitten@flmnh.ufl.edu; email for Williams: orchid@flmnh.ufl.edu). Phylogenetic relationships of Scaphyglottis and related genera (Laeliinae: Orchidaceae) based on nrDNA ITS sequence data. Brittonia 56: 58–66. 2004.—Sequences of the nuclear ribosomal internal transcribed spacer regions 1 & 2 (nrDNA ITS) including the intervening 5.8S region were analyzed cladistically for 43 individuals of 35 species of Scaphyglottis s.l. plus two outgroup taxa. Low levels of sequence divergence do not allow estimation of relationships among most clades, but the analyses indicate that four segregate genera (Hexisea Lindl., Reichenbachanthus Barb. Rodr., Hexadesmia Brogn., and Platyglottis coriacea L.O. Williams) are embedded within a broad paraphyletic Scaphyglottis. This broadly defined Scaphyglottis sensu Dressler is characterized within Laeliinae by the usual presence of superposed growth habit and the presence of a column foot. In order to accommodate species formerly placed in Platyglottis and Reichenbachanthus, three new combinations are made in Scaphyglottis: Scaphyglottis brasiliensis (Schltr.) Dressler, S. coriacea (L. O. Williams) Dressler, and S. emarginata (Garay) Dressler. Key words: Orchidaceae, Laeliinae, Scaphyglottis, Hexisea, Reichenbachanthus, Platyglottis, ITS. The genus Scaphyglottis Poepp. & Endl. s.l. has attracted little horticultural attention relative to showier members of Laeliinae, but it is of some botanical interest because of its unusual superposed growth habit. There are about 55 species that are diverse in several vegetative and floral features, and the exact delimitation of generic boundaries has remained uncertain. The genus ranges from Mexico to southern Brazil, but the bulk of the species, about 70%, occurs in Costa Rica and/or Panama. The lectotype of the genus is Scaphyglottis graminifolia (Ruiz & Pav.) Poepp. & Endl. Genera that are entangled with Scaphyglottis include Hexisea Lindl., Reichenbachanthus Barb. Rodr., Hexadesmia Brogn., Platyglottis L. O. Williams, Helleriella A. D. Hawkes, Pachystele Schltr., Leaoa Schltr. & Porto, Costaricaea Schltr., and Tetragamestus Rchb.f. Scaphyglottis was revised by Adams (1993); he suggested networks of relationships but did not include a phylogenetic analysis. The recent molecular phylogeny of Laeliinae (van den Berg et al., 2000) included 18 members of the Scaphyglottis alliance, but the authors did not address taxonomic concepts within this clade or make any nomenclatural transfers. As shown by van den Berg et al. (2000), Scaphyglottis is closely related to Acrorchis and Jacquiniella. At one time, the genera Brittonia, 56(1), 2004, pp. 58–66. q 2004, by The New York Botanical Garden Press, Bronx, NY 10458-5126 U.S.A. ISSUED: 02 January 2004 2004] DRESSLER ET AL.: SCAPHYGLOTTIS (ORCHIDACEAE) having a prominent column foot were treated as the subtribe Ponerinae (Schlechter, 1926), but the current molecular data indicate that Schlechter’s Ponerinae is polyphyletic. Baker (1972), on evidence from vegetative anatomy, suggested that there are two different complexes having a prominent column foot in the Laeliinae, and recent molecular analysis has supported this idea, with Homalopetalum, Domingoa, and Nageliella being well separated from Scaphyglottis (van den Berg et al., 2000). Further, van den Berg et al. (2000) showed that Ponera, Isochilus, and Helleriella form a highly supported clade, thus reviving the subtribe Ponerinae. Many species of Scaphyglottis have superposed stems, producing one to several new shoots at the apices of older shoots so that the plants become superficially shrublike. Not all species produce superposed growths, and this habit is variable in some species. Scaphyglottis typically has a prominent column foot with the lip hinged to it, but Tetragamestus has been characterized as lacking a column foot, and S. geminata Dressler & Mora-Retana and species assigned to Hexisea have an immobile lip rigidly attached to the column foot. The genus Hexisea has been interpreted in diverse ways. The type species H. bidentata Lindl. and the similar H. imbricata (Lindl.) Rchb.f. have ellipsoid pseudobulbs and orange red flowers with a prominent nectary and conspicuously bent lip that has been characterized as sigmoid. Ames (1937) included Reichenbachanthus and all Scaphyglottis species with prominent nectaries and terete leaves in Hexisea. Dressler (1979) limited Hexisea to five species with yellow, orange, or red flowers indicative of hummingbird pollination. Adams (1988, 1993) further restricted Hexisea to H. bidentata and H. imbricata, assigning the other putatively hummingbird-pollinated species to Scaphyglottis, and suggested that S. sigmoidea (Ames & C. Schweinf.) B. R. Adams and S. arctata (Dressler) B. R. Adams were independently derived from different species of the Pachystele complex. Adams had not seen S. gentryi Dodson & M. Monsalve (described in 1998), a species with green and white flowers but otherwise 59 very similar to Hexisea in both plant and flower. Pollinium number varies (four or six) within Scaphyglottis and related genera; Hexadesmia was erected to unite those species with six pollinia, emphasizing this floral character over others. Adams also suggested that Hexadesmia micrantha Lindl. is not a member of Scaphyglottis. The name Pseudohexadesmia, used for this species by Brieger (1992), has not been validly published. The present study was undertaken to examine monophyly and relationships within and among Scaphyglottis and related genera using molecular data, and to evaluate homoplasy in selected morphological characters that traditionally have been used to define genera in Laeliinae. Materials and Methods SAMPLING Table 1 is a list of specimens sampled, their vouchers, and their GenBank numbers. Most taxa were grown at the Florida Museum of Natural History, Gainesville, and voucher specimens were prepared when they flowered. AMPLIFICATION AND SEQUENCING Protocols for amplification and sequencing are given in Whitten, Williams and Chase (2000). Some trial amplifications utilizing the ITS primers ITS 5 & 4 of Baldwin et al. (1995) under conditions of low stringency (518C annealing temperature) produced highly divergent ITS sequences that were apparent paralogues. Sequences produced using the primers of Sun et al. (1994) combined with the use of betaine (1.0 M) in the PCR mix and a higher annealing temperature (608C) yielded longer and apparently orthologous sequences. Outgroup taxa were selected based upon results of van den Berg et al. (2000); their cladograms placed a clade composed of Acrorchis roseola Dressler, Jacquiniella Schltr., and Briegeria Senghas (a segregate of Jacquiniella) as sister to the Scaphyglottis clade in the most parsimonious trees, although without high bootstrap support. DNA sequences were aligned manually 60 [VOL. 56 BRITTONIA TABLE I OF TAXA EXAMINED, VOUCHERS, AND GENBANK NUMBERS. VOUCHERS ARE DEPOSITED AT FLAS UNLESS OTHERWISE NOTED. SOME SPECIES ARE REPRESENTED BY TWO OR THREE INDIVIDUALS (DESIGNATED A, B, C); THESE LETTERS CORRESPOND TO THOSE ON FIG. 1 LIST Individual Taxon Acrorchis roseola Dressler Hexisea imbricata (Lindl.) Rchb.f. Jaquiniella globosa (Jacq.) Schltr. Platyglottis coriacea L. O. Williams Reichenbachanthus cuniculatus (Schltr.) Pabst R. reflexus (Lindl.) Brade Scaphyglottis amparoana (Schltr.) Dressler S. arctata (Dressler) B. R. Adams S. behrii (Rchb.f.) Benth. & Hook. f. ex Hemsl. S. bilineata (Rchb.f.) Schltr. S. chlorantha B. R. Adams S. sp. nov. S. confusa (Schltr.) Ames & Correll S. corallorrhiza (Ames) Ames, F. T. Hubb. & C. Schweinf. S. crurigera (Bateman ex Lindl.) Ames & Correll S. densa (Schltr.) B. R. Adams S. fusiformis (Griseb.) Schult. S. geminata Dressler & Mora-Retana S. S. S. S. S. S. S. gentryi Dodson & M. Monsalve gigantea Dressler graminifolia (Ruiz & Pav.) Poepp. & Endl. jimenezii Schltr. leucantha Rchb.f. lindeniana (A. Rich. & Galeotti) L. O. Williams livida (Lindl.) Schltr. A B A B A B S. longicaulis S. Watson S. mesocopis (Endres & Rchb.f.) Benth. & Hook.f. ex Hemsl. S. micrantha (Lindl.) Ames & Correll A B S. minutiflora Ames & Correll S. modesta (Rchb.f.) Schltr. S. S. S. S. S. S. S. S. pachybulbon (Schltr.) Dressler prolifera Cogn. pulchella (Schltr.) L. O. Williams punctulata (Rchb.f.) C. Schweinf. aff. punctulata (Rchb.f.) C. Schweinf. sigmoidea (Ames & C. Schweinf.) B. R. Adams spathulata C. Schweinf. stellata Lodd. ex Lindl. and gaps were coded as missing values. The ends of matrices were trimmed to exclude sequencing artifacts. The aligned data matrix is available from the authors or from GenBank as a ‘‘Popset.’’ All cladistic analyses were performed using PAUP* version 4.0b10 (Swofford, 2000). A B C Voucher Dressler 6103 (MO) Dressler 6331 Atwood 89–219 Dressler 6339 Dressler 6147 Dressler 6320 Dressler 6299 Dressler 6224 Dressler 3379 Dressler 6328 Dressler 6353 Dressler 6287 Dressler 6318 Dressler 6285 Dressler 6201 Dressler 6312 Dressler 6354 Dressler 6355 Dressler 6293 Dressler 6304 Dressler 6319 Dressler 6223 Dressler 6325 Dressler 6302 Dressler 6315 Dressler 6295 Dressler 6343 Dressler 6327 Dressler 6326 Dressler 6300 Dressler 6209 Dressler 6303 Dressler 6307 Dressler 6294 Ackerman 3074 (UPRRP) Dressler s.n. Dressler 6286 Dressler 6310 Dressler 6317 Dressler 6301 Dressler 6311 Dressler 6321 Dressler 6308 Dressler 6306 Dressler 6305 GenBank # AY174761 AY174749 AY174760 AY174759 AY174752 AY174753 AY174754 AY174743 AY174724 AY174718 AY174745 AY174757 AY174755 AY174744 AY174727 AY174751 AY174726 AY174758 AY174738 AY174737 AY174748 AY174725 AY174732 AY174750 AY174731 AY174735 AY174717 AY174746 AY174728 AY174733 AY174741 AY174742 AY174729 AY174730 AY174756 AY174722 AY174723 AY174736 AY174719 AY174740 AY174720 AY174721 AY174747 AY174739 AY174734 SEARCH STRATEGIES The matrix was subjected to 1000 replicates of random taxon entry additions, MULTREES on, using subtree pruning and regrafting (SPR) swapping, but saving only five trees per replicate. The resulting short- 2004] DRESSLER ET AL.: SCAPHYGLOTTIS (ORCHIDACEAE) est trees from this search were used as starting trees and were swapped to completion using SPR. Confidence limits for trees were assessed by performing 1000 replicates of heuristic bootstrapping (Felsenstein, 1985) using equal weighting, SPR swapping, MULTREES on, and holding only ten trees per replicate. Results The matrix consisted of 748 aligned bases. Of these, 582 characters were constant, 88 variable characters (15%) were parsimony-uninformative, and 78 characters were parsimony-informative. The cladistic analysis yielded 42 shortest trees (ACCTRAN optimization; length 5 252 steps, consistency index (CI) 5 0.78, CI excluding uninformative characters 5 0.65, retention index (RI) 5 0.86). Figure 1 is a randomly chosen single tree with bootstrap (BS) values added; squares indicate nodes that collapse in the strict consensus of all 42 shortest trees. Discussion As is characteristic of most Laeliinae (van den Berg et al., 2000), nrDNA ITS sequences of Scaphyglottis species exhibit comparatively low levels of sequence divergence with correspondingly low bootstrap values at many nodes of the resulting trees. These low bootstrap values preclude detailed conclusions about relationships within the Scaphyglottis complex. Additional sequence data from plastid regions such as trnL-F are desirable, but preliminary data (Whitten, unpubl.) indicate that considerably more sequence data will be required for adequate resolution of species relationships. Nevertheless, the analyses of van den Berg et al. (2000) indicate that trees based on nrDNA ITS alone might accurately represent generic relationships within Laeliinae, even though strong bootstrap support is lacking. In spite of its limitations, the ITS tree (Fig. 1) shows, with strong bootstrap support (94%), that Reichenbachanthus, Hexisea, and Platyglottis are embedded within a broad Scaphyglottis. In the analyses of van den Berg et al. (2000), the sequence of 61 Platyglottis was generated from a non-flowering, unvouchered plant; our sequence from a vouchered specimen confirms the identity and placement of Platyglottis. The only large ingroup clade with strong bootstrap support is the Pachystele clade; this clade includes most of the species that have been placed in Hexisea, even in the broad sense used by Ames and his colleagues (Ames, 1937). The species assigned to Pachystele by Schlechter (S. corallorrhiza (Ames) Ames, F. T. Hubb. & C. Schweinf., S. densa (Schltr.) B. R. Adams, and S. jimenezii Schltr.) as well as the similar S. fasciculata Hook. and S. confusa (Schltr.) Ames & Correll, possess relatively slender stems and short, wide columns with a distinct nectary. Other well-supported clades include S. chlorantha B. R. Adams 1 S. densa (99% BS), S. lindeniana (A. Rich. & Galeotti) L. O. Williams 1 S. pachybulbon (Schltr.) Dressler (98% BS), and S. crurigera (Bateman ex Lindl.) Ames & Correll 1 S. micrantha (Lindl.) Ames & Correll (95% BS). The deeper nodes of the tree lack strong bootstrap support. This clade or grade includes most species with six pollinia (the Hexadesmia grade) and a complex of species with 4 pollinia, including S. graminifolia, the lectotype of the genus, and the majority of the species in the genus. In general, the relationships within Scaphyglottis agree with the scheme offered by Adams (1993), but Reichenbachanthus, Hexisea in the strictest sense, and Scaphyglottis (Hexadesmia) micrantha are embedded within Scaphyglottis. If Adams had seen material of Scaphyglottis gentryi Dodson & Monsalve, he might have recognized a closer relationship between Scaphyglottis and Hexisea. The flower color of Scaphyglottis gentryi (green sepals and a white lip) is similar to many Scaphyglottis species, but the nectary, the vegetative features, and the prominent floral bracts are similar to those of Hexisea imbricata. The genus Hexisea has priority over Scaphyglottis (Dressler, 1994), but Scaphyglottis has been conserved against Hexisea (Brummitt, 1996). In our molecular analyses, both Hexisea and Reichenbachanthus are embedded in one of the major clades of Scaphyglottis. Rather than split Scaphyglot- 62 BRITTONIA [VOL. 56 FIG. 1. One of 42 equally parsimonious trees resulting from cladistic analysis of nrDNA ITS 1 & 2 data. Fitch branch lengths are above lines, with bootstrap values below lines. Nodes that collapse in the strict consensus of all equally parsimonious trees are indicated with a square. Taxa with six pollinia (Hexadesmia Brogn.) are indicated with a number ‘‘6’’ to the right of the binomial; all other taxa bear four pollinia. Some species are represented by two or three individuals; letters (A, B, C) distinguish individual samples. The entire ingroup constitutes Scaphyglottis sensu Dressler (this paper). 2004] DRESSLER ET AL.: SCAPHYGLOTTIS (ORCHIDACEAE) tis into several genera that lack clear morphological synapomorphies, we prefer to lump these genera into a more broadly defined Scaphyglottis that is defined by the superposed growth habit (with a few apparent reversals) and the presence of a column foot. Some necessary combinations have already been published (Dressler, 2002); the remaining new combinations are made below. The other Mesoamerican species of Reichenbachanthus already have valid names in Scaphyglottis. MORPHOLOGICAL FEATURES OF SCAPHYGLOTTIS SENSU DRESSLER The lack of resolution and support within Scaphylottis makes the plotting of morphological characters onto the tree an exercise of questionable utility, but several morphological characters merit discussion in relation to the cladogram. Habit. Scaphyglottis species sensu Dressler show sympodial growth with the inflorescences produced at the stem apices. In most species, however, ‘‘superposed’’ stems are also produced. In each season of growth, the youngest stems produce new basal shoots, and each of the older stems usually produces one to several subterminal shoots. Thus, with time, a bushy habit with several to many layers of superposed stems is produced, with the superposed stems usually progressively smaller. The superposed growth habit appears to be ancestral in Scaphyglottis, but superposed stems are lacking in several species of the Hexadesmia grade (Fig. 1). Superposed growth habits similar to that of Scaphyglottis are found also in Trichosalpinx Luer and Brachionidium Lindl. of the Pleurothallidinae and in Otochilus Lindl. and some species of Pholidota Lindl. ex Hook. of the Old World Coelogyninae. Pseudobulbs. In most species of Scaphyglottis, the stems are thickened, forming distinct pseudobulbs. In the Pachystele clade and in some species of the Hexadesmia grade, the pseudobulbs are long stipitate. In some species of the Pachystele clade, the basal stems are scarcely thickened, but the superposed stems are more markedly thickened. In most species of the 63 S. graminifolia grade, the pseudobulbs are short-stipitate or subsessile. Reichenbachanthus species lack prominent pseudobulbs and possess very narrow, terete leaves. Leaf distribution. In addition to one or a few subterminal leaves, the stems bear sheaths, and the sheaths often bear shortlived, rudimentary leaf blades. In some populations of Scaphyglottis punctulata (Rchb. f) C. Schweinf. (and also in the unsampled S. monspirrae Dressler), the blades on the sheaths are similar to those at the stem apex and they persist on the stem. These forms of S. punctulata have slender, non-thickened stems, and were thus assigned to Helleriella by Garay and Sweet (1974). The habit of S. punctulata, however, is typical of Scaphyglottis, with subterminal inflorescences and branching only near the stem apices. Interestingly, Platyglottis coriacea has a habit similar to that of Helleriella, with slender stems, cauline leaves, irregular branching, both terminal and lateral inflorescences, and six pollinia (vs. four in Helleriella). Because of these vegetative similarities, we had expected Platyglottis to be closely related to Helleriella, but the molecular data do not support this hypothesis. The S. aff. punctulata from Ecuador (Dressler 6321) produces prominent pseudobulbs and lacks persistent lateral leaves; this specimen probably represents an undescribed species distinct from S. punctulata. Column foot. The column foot is a basal outgrowth of the column fused to the labellum. Schlechter (1926) placed all genera of Epidendreae with a prominent column foot in subtribe Ponerinae, resulting in an artificial classification. Using anatomical data, Baker (1972) suggested that there are two different complexes with a prominent column foot in Laeliinae; recent molecular data support his idea, with Homalopetalum, Domingoa, and Nageliella well separated from Scaphyglottis (van den Berg et al., 2000). Their molecular data also show that Ponera, Isochilus, and Helleriella form a highly supported clade, thus reviving a narrower subtribe Ponerinae. The column foot has been regarded as a synapomorphy for Scaphyglottis (although not a unique one within Laeliinae), and the segregate Tetra- 64 [VOL. 56 BRITTONIA gamestus was said to differ in lacking a column foot. It would be more accurate to say that the length of the column foot varies greatly within the genus, but is always present to some degree. In most cases, the lip is hinged to the apex of the column foot, although it is rigid in S. geminata and is not markedly hinged in the species that have been assigned to Hexisea. Nectaries. There is usually a distinct nectary on the column foot or at the base of the lip. We do not have detailed observations on the presence/absence of nectar, and some taxa might possess false nectaries and a deceit pollination syndrome; more careful observations are needed. The column foot is concave with a prominent nectary in Scaphyglottis amparoana and S. gigantea. In the species treated as Reichenbachanthus, there is a deep, tubular nectary, and the lip is more or less thickened distal to the nectary. In S. gentryi, S. sigmoidea, S. arctata, Hexisea bidentata, and H. imbricata, there are deep and more or less concealed nectaries. In S. sigmoidea, the combined lip and column foot are truly sigmoid, but in most other species the structure is only slightly ‘‘S’’-shaped and the details are different in each species. Flower color. Most Scaphyglottis species have small green, tan, or white flowers. The molecular and vegetative characters indicate that the reddish-flowered Hexisea, in any sense, is embedded within Scaphyglottis. Species with red/orange flowers indicative of bird pollination form an unresolved, poorly supported clade within the Pachystele clade; these include Hexisea imbricata, H. bidentata (not sampled), S. corallorrhiza, S. arctata, S. jimenezii, and S. sigmoidea. Adams (1993) suggested that S. sigmoidea and S. corallorrhiza are sister taxa. Scaphyglottis gentryi lacks red coloration but possesses a prominent, deep nectary and also falls within this clade. Scaphyglottis aurea (Rchb.f.) Foldats (not sampled), a South American species that might also show adaptations to ornithophily, is probably a member of the S. graminifolia clade. If so, S. aurea would represent an independent evolution of ornithophily within Scaphyglottis. Number of pollinia. There are six pol- linia in the species that have been treated as Hexadesmia (Fig. 1) and four in all other species and the outgroups. Since the taxa with six pollinia do not form a well-supported clade, the generic concept of Hexadesmia, based solely upon pollinium number, should be abandoned. Rostellar structure. In most species, only an irregular portion of the rostellar glue is removed by the pollinator, but in a few there is a distinct (removable) viscidium, taken as a unit with the pollinia. This is prominent in Scaphyglottis sigmoidea, but is evident also in S. graminifolia and in most species that have been treated as Pachystele. In summary, all the morphological features of Scaphyglottis sensu Dressler exhibit some degree of homoplasy, so no single key character can be used to distinguish all Scaphyglottis from other Laeliinae. The genus is characterized by the usual presence of both the superposed growth habit and a column foot. NOMENCLATURAL CHANGES COMBINATIONS AND NEW Scaphyglottis brasiliensis (Schltr.) Dressler, comb. nov. Fractiunguis brasiliensis Schltr., An. Mem. Inst. Butantan I (4): 56. 1922. Reichenbachanthus modestus Barb. Rodr., non Scaphyglottis modesta (Rchb.f.) Schltr. Scaphyglottis coriacea (L. O. Williams) Dressler, comb. nov. Platyglottis coriacea L. O. Williams, Ann. Missouri Bot. Gard. 29: 347, t. 34. 1942. Scaphyglottis emarginata (Garay) Dressler, comb. nov. Reichenbachanthus emarginatus Garay, Bot. Mus. Leafl. 21: 255. 1967. Hexisea reflexa Rchb.f., Linnaea 41: 131. 1877, non Scaphyglottis reflexa Lindl. Generic Synonymy of Scaphyglottis Hexisea Lindl., 1834. TYPE: H. bidentata Lindl. Scaphyglottis Poepp. & Endl., Nov. Gen. Sp. Pl. 1: 58. 1836. 2004] DRESSLER ET AL.: SCAPHYGLOTTIS (ORCHIDACEAE) Conserved against Hexisea; lectotype: Fernandezia graminifolia Ruiz & Pav.; Dressler, 1960. Cladobium Lindl., Intr. Nat. Syst. Bot., ed. 2: 446. 1836. TYPE: C. violaceum Lindl. 5 S. graminifolium. Hexadesmia Brongn., Ann. Sci. Nat. Bot. ser. 2, 17: 44. 1842. TYPE: H. fasciculatum Brongn. 5 S. lindeniana. Tetragamestus Rchb.f., Bonplandia 2: 21. 1854. TYPE: not designated; two species cited in protologue: T. modesta Rchb.f. and T. aurea (Rchb.f.) Rchb.f. Reichenbachanthus Barb. Rodr., Gen. Sp. Orchid. Nov. 2: 164. 1882. TYPE: R. modestus 5 S. brasiliensis. Fractiunguis Schltr., Ann. Mem. Inst. Butantan 1: 55. 1922. TYPE: not designated; two species cited in protologue: F. reflexa (Rchb.f.) Schltr. and F. brasiliensis Schltr. Leaoa Schltr. & Campos Porto, Arch. Jard. Bot. Rio de Janeiro 3: 292. 1922. TYPE: L. monophylla 5 S. livida. Pachystele Schltr., Repert. Spec. Nov. Regni Veg. Beih. 19: 28, 114. 1923. TYPE: not designated; two species cited in protologue: P. densa Schltr. and P. jimenezii. Costaricaea Schltr., Repert. Spec. Nov. Regni Veg. Beih. 19: 30. 1923. TYPE: C. amparoana Schltr. Ramonia Schltr., Repert. Spec. Nov. Regni Veg. Beih. 19: 294. 1923. TYPE: R. pulchella Schltr. Platyglottis L. O. Williams, Ann. Missouri Bot. Gard. 29: 345. 1942. TYPE: P. coriacea. Acknowledgments We thank G. Staal, F. Pupulin, Petite Plaisance Orchids, and Marie Selby Botan- 65 ical Gardens for sharing living material with us, and Katia Silvera for assistance with lab work. This study was funded in part by the Florida Museum of Natural History, by NSF grant DEB 9815821 to NHW, and by grants from the American Orchid Society. Literature Cited Adams, B. R. 1988. New species and combinations in the genus Scaphyglottis (Orchidaceae). Phytologia 64: 249–258. ———. 1993. A taxonomic revision of the genus Scaphyglottis Poepp. & Endl. (Orchidaceae-Epidendroideae). Ph.D. dissertation, Southern Illinois University, Carbondale. Ames, O. 1937. Orchidaceae. In: P. C. Standley, editor. Flora of Costa Rica. Field Mus. Nat. Hist. Bot. Ser. 28: 197–306. Baker, R. K. 1972. Foliar anatomy in the Laeliinae (Orchidaceae). Ph.D. dissertation. Washington University, St. Louis. Baldwin, B. G., M. J. Sanderson, J. M. Porter, M. F. Wojceichowski, D. S. Campbell & M. J. Donoghue. 1995. The ITS region of nuclear ribosomal DNA: a valuable source of evidence on angiosperm phylogeny. Ann. Missouri Bot. Gard. 82: 247–277. Brieger, F. G. 1992. Subtribus Epidendrinae: Pseudohexadesmia. Pages 487–488. In: F. G. Brieger, R. Maatsch & K. Senghas, editors. Schlecter’s Die Orchideen 1/A. 3rd ed. Verlag Paul Paray, Berlin. Brummitt, R. K. 1996. Report of the Committee for Spermatophyta: 44. Taxon 45: 671–681. Dressler, R. L. 1960. Nomenclatural notes on the Orchidaceae I. Taxon 9: 213–214. ———. 1979. Una Hexisea distintiva de Panamá, Hexisea arctata Dressler. Orquı́dea (Méx.) 7: 215– 225. ———. 1994. Proposal to conserve Scaphyglottis against Hexisea (Orchidaceae). Taxon 43: 665–666. ———. 2002. New species and combinations in Costa Rican orchids. Lankesteriana 3: 25–29. Felsenstein, J. 1985. Confidence limits on phylogenies: an approach using the bootstrap. Evolution 39: 783–791. Garay, L. A. & H. R. Sweet. 1974. Orchidaceae. In: R. A. Howard, editor. Flora of the Lesser Antilles. Arnold Arboretum, Harvard University, Jamaica Plain, Massachusetts. Schlechter, R. 1926. Das System der Orchidaceen. Notizbl. Bot. Gart. Mus. Berlin-Dahlem 9: 563– 591. Sun, Y., D. Z. Skinner, G. H. Liang & S. H. Hulbert. 1994. Phylogenetic analysis of Sorghum and related taxa using internal transcribed spacers of nuclear ribosomal DNA. Theoret. Appl. Genet. 89: 26–32. 66 BRITTONIA Swofford, D. L. 2000. PAUP*: phylogenetic analysis using parsimony (*and other methods). Version 4.0b10. Sinauer, Sunderland, Massachusetts, USA. van den Berg, C., W. E. Higgins, R. L. Dressler, W. M. Whitten, M. A. Soto Arenas, A. Culham & M. W. Chase. 2000. A phylogenetic analysis of Laeliinae (Orchidaceae) based on sequence data [VOL. 56 from internal transcribed spacers (ITS) of nuclear ribosomal DNA. Lindleyana 15: 96–114. Whitten W. M., N. H. Williams & M. W. Chase. 2000. Subtribal and generic relationship of Maxillarieae (Orchidaceae) with emphasis on Stanhopeinae: combined molecular evidence. Amer. J. Bot. 87: 1842–1856.