Alec M. Pridgeon’s research while affiliated with Royal Botanic Gardens, Kew and other places

A phylogenaetic hypothesis for tribe Podochileae with emphasis on subtribe Eriinae s.s. is based on nucleotide sequences of the nuclear ITS and four plastid regions (matK, trnL-F spacer, trnL intron and ycf1). The strict consensus tree based on parsimony is largely congruent with the maximum likelihood tree with a few major differences; most importantly, monophyly of Podochileae as recently circumscribed is strongly supported by the maximum likelihood tree but not recovered in the parsimony analysis. Monophyly of Thelasiinae s.s. (without Ridleyella) and Eriinae s.l. (including Podochilinae) is supported, whereas Eria s.l. appears polyphyletic. The generic circumscription of Eriinae s.s. (excluding Podochilinae) is revised, and 21 genera are accepted, including two not previously recognized. Nomenclatural changes and a key to genera in Eriinae are provided.

Most of the species studied in this paper have previously been placed in either Pleurothallis or Lepanthes. However, at one time or another, members of the group have also been placed in the genera Andinia, Brachycladium, Lueranthos, Masdevalliantha, Neooreophilus, Oreophilus, Penducella, Salpistele and Xenosia. Phylogenetic analyses of nuclear ITS and plastid matK sequences indicate that these species form a strongly supported clade that is only distantly related to Lepanthes and is distinct from Pleurothallis and Salpistele. Since this clade includes the type species of Andinia, A. dielsii, and it has taxonomic precedence over all other generic names belonging to this group, Andinia is re-circumscribed and expanded to include 72 species segregated into five subgenera: Aenigma, Andinia, Brachycladium, Masdevalliantha and Minuscula. The required taxonomic transfers are made herein. We hypothesize that convergent evolution towards a similar pollinator syndrome involving deceit pollination via pseudocopulation by Diptera resulted in a similar floral morphology between species of subgenus Brachycladium and species of Lepanthes; hence the prior placement of the species of subgenus Brachycladium in Lepanthes. Species of the re-circumscribed Andinia are confined exclusively to the Andes, ranging from about 1,200 to 3,800 m, from Colombia south to Bolivia, making the generic name very apt. Elevational distributions of the individual clades are discussed in relation to the possible evolutionary diversification of the most species-rich clade, subgenus Brachycladium.

The phylogenetic relationships within Specklinia (Pleurothallidinae; Orchidaceae) and related genera are re-evaluated using Bayesian analyses of nrITS and chloroplast matK sequence data of a wide sampling of species. Specklinia is found paraphyletic in the DNA based trees, with species alternatively assigned to Muscarella proven distinct, monophyletic and easily recognizable. Specklinia as such includes about 100 morphologically highly diverse species. Their phenotypic differences have prompted the creation of up to eleven generic names within this relatively small group. Here we show not only that these morphologically divergent species are closely related, but also that they can still be recognized by certain conserved morphological traits. The genera Acostaea, Areldia, Empusella, Cucumeria, Gerardoa, Pseudoctomeria, Sarcinula, Sylphia, Tribulago and Tridelta are found embedded within Specklinia, and therefore reduced under the synonymy of the latter. Specklinia is confirmed as sister to a clade that includes Platystele, Scaphosepalum and Teagueia. Five well-supported subgenera are proposed for Specklinia and are characterized both geographically and morphologically. The species belonging to each subgenus are listed. Incaea is synonymized with Dryadella, while Rubellia is reduced under Platystele. New combinations for several species are proposed. The criteria for the generic delimitation of Specklinia and other genera in the Pleurothallidinae are discussed.

div class="page" title="Page 1"> Subtribe Pleurothallidinae (Epidendreae: Orchida- ceae) comprises an estimated 4000 Neotropical species in about 30 genera (Luer 1986), accounting for 15-20% of the species in the entire family. </div

Since the last classification of Orchidaceae in 2003, there has been major progress in the determination of relationships, and we present here a revised classification including a list of all 736 currently recognized genera. A number of generic changes have occurred in Orchideae (Orchidoideae), but the majority of changes have occurred in Epidendroideae. In the latter, almost all of the problematic placements recognized in the previous classification 11 years ago have now been resolved. In Epidendroideae, we have recognized three new tribes (relative to the last classification): Thaieae (monogeneric) for Thaia, which was previously considered to be the only taxon incertae sedis; Xerorchideae (monogeneric) for Xerorchis; and Wullschlaegelieae for achlorophyllous Wullschlaegelia, which had tentatively been placed in Calypsoeae. Another genus, Devogelia, takes the place of Thaia as incertae sedis in Epidendroideae. Gastrodieae are clearly placed among the tribes in the neottioid grade, with Neottieae sister to the remainder of Epidendroideae. Arethuseae are sister to the rest of the higher Epidendroideae, which is unsurprising given their mostly soft pollinia. Tribal relationships within Epidendroideae have been much clarified by analyses of multiple plastid DNA regions and the low-copy nuclear gene Xdh. Four major clades within the remainder of Epidendroideae are recognized: Vandeae/Podochileae/Collabieae, Cymbidieae, Malaxideae and Epidendreae, the last now including Calypsoinae (previously recognized as a tribe on its own) and Agrostophyllinae s.s. Agrostophyllinae and Collabiinae were unplaced subtribes in the 2003 classification. The former are now split between two subtribes, Agrostophyllinae s.s. and Adrorhizinae, the first now included in Epidendreae and the second in Vandeae. Collabiinae, also probably related to Vandeae, are now elevated to a tribe along with Podochileae. Malaxis and relatives are placed in Malaxidinae and included with Dendrobiinae in Malaxideae. The increased resolution and content of larger clades, recognized here as tribes, do not support the ‘phylads’ in Epidendroideae proposed 22 years ago by Dressler. © 2014 The Linnean Society of London, Botanical Journal of the Linnean Society, 2015, 177, 151–174.

For centuries orchids have been among the most popular of plant families, with thousands of species and hybrids cultivated worldwide for the diversity, beauty, and intricacy of their flowers. The Genera Orchidacearum series represents a robust and natural classification of the orchids, something that has eluded plant scientists and orchid enthusiasts for years. The editors, who are all distinguished orchid specialists, incorporate a wealth of new DNA data into a truly phylogenetic classification, identifying the areas and taxa that merit additional work. To this end, they have invited several international specialists to contribute in their particular areas of expertise. Each volume provides comprehensive coverage of one or two orchid subfamilies and the series as a whole will be an indispensable reference tool for scientists, orchid breeders and growers. Orchidaceae is the largest monocotyledon family and perhaps the largest plant family in terms of number of species, approximately 25,000. However, for a variety of reasons it remains one of the least understood. The fossil record is poor, and active research has been relatively scarce until recent years, in part because of the sheer size and cosmopolitan distribution of the family. The fifth volume treats 186 genera in tribe Cymbidieae of the largest subfamily, Epidendroideae, including some of the showiest orchids often used in hybridizing. Comprehensive treatments are provided for each genus, which include complete nomenclature, description, distribution (with map), anatomy, palynology, cytogenetics, phytochemistry, phylogenetics, pollination, ecology, and economic uses. Cultivation notes are included for those genera known to be in hobbyist collections. Genera are beautifully illustrated with line drawings and colour photographs.

A cladistic analysis of subtribe, Pleurothallidinae (Orchidaceae) is based on 45 anatomical/ morphological characters. The ingroup members comprise 24 genera; the large genus Pleurothallis consists of two subgenera and ten species complexes. Three taxa representing subtribes Laeliinae and Arpophyllinae are designated as outgroup. Eight most parsimonious trees were discovered using computer assisted software (length = 230; CI = 0.27). The hypothesis that subtribe Pleurothallidinae has undergone a unilinear reduction in the number of pollinia is not supported by this study. Although the eight-pollinia state as represented by Octomeria apparently is plesiomorphic, the two-pollinia and four-pollinia states arose early in the phylogeny of the subtribe. Both two-and four-pollinia states subsequently reappeared as parallelisms. The six-pollinia state exhibited in Brachionidium is autapomorphic. This cladistic analysis suggests that Pleurothallis is not a natural genus and, perhaps may be divided into several discrete genera.

Leaf anatomy of 25 species in 15 genera of Caladeniinae (Diurideae, Orchidaceae), excluding Caladenia, was investigated to determine diagnostic characters to be used in forthcoming, broad-based cladistic analyses of the subtribe and to assess interspecific and intergeneric relationshipS. Of the characters examined, those that show the most variation among the study taxa are presence and types of trichomes, cuticular sculpturing, anticlinal walls of epidermal cells, heterogeneity of chlorenchyma, distribution and length: width ratios of stomata. Anatomical evidence supports the generic concept of Leptoceras Lindley but contradicts that of Drakonorchis Hopper & A.P. Brown.Paracaleana is not sufficiently distinct from Caleana to warrant generic status.Lyperanthus serratus and L.suaveolens are hyperstomatic, a rare condition in Orchidaceae. On the basis of these and other characters, Lyperanthus, as currently circumscribed, is polyphyletic. From leaf structure Caladeniinae as now conceived is polyphyletic and comprises seven groups: (1) Caladenia, Leptoceras, Elythranthera, Eriochilus, Glossodia, Aporostylis; (2) Adenochilus, Rimacola; (3) Arthrochilus, Chiloglottis, Spiculaea, Leporella; (4) Caleana (including Paracaleana); (5) Bumettia; (6) Lyperanthus suaveolens and L.serratus; (7) Lyperanthus nigricans.