SMITHSONIAN CONTRIBUTIONS TO BOTANY NUMBER 61 A Phylogenetic Analysis of the-Orchidaceae Pamela Burns-Balogh and V.A. Funk SMITHSONIAN INSTITUTION PRESS City of Washington 1986 ABSTRACT Burns-Balogh, Pamela, and V.A. Funk. A Phylogenetic Analysis of the Orchidaceae. Smithsonian Contributions to Botany, number 6 1, 79 pages, 94 figures, 4 plates, 1986.-The Orchidaceae is the largest flowering plant family, with approximately 25,000 species. Sixty-eight apomorphies grouped into forty-two transformation series were used to construct a cladogram for the twenty-six tribes of the family. A detailed discussion of the characters is followed by an in-depth analysis of the cladogram. The cladogram was used to develop a classification and a natural key to the tribes. Seven subfamilies (Neuwiedioideae, Apostasioideae, Cypripedioideae, Spiranthoideae, Neot- tioideae, Orchidoideae, and Epidendroideae) are divided into 20 tribes, the majority of which are defined by synapomorphies. Of the intrasubfamily classifications, that of the Epidendroideae is the most tenuous. The phylogeny and classification presented here are hypotheses of relationship and are therefore subject to change as more information becomes available. OFFICIALPUBLICATION DATE is handstamped in a limited number of initial copies and is recorded in the Institution’s annual report, Smithsonian Year. SERIES COVER DESIGN: Leaf clearing from the katsura tree Cerecidiphyllum japonicum Siebold and Zuccarini. Library of Congress Cataloging in Publication Data Burns-Balogh, Pamela. A phylogenetic analysis of the Orchidaceae. (Smithsonian contributions to botany ; no. 61) Bibliography: p. Supt. of Docs. no.: SI 1.29: 61 1. Orchids-Classification. 2. Cladistic analysis. 3. Plants-Phylogeny. I. Funk, V. A. (Vicki A.), 1947- . 11. Title. 111. Series. QKl.S2747 no. 61 581s [584’.15’012] 85-600315 [QK495.064] Contents Page Introduction ............................................ 1 Acknowledgments .................................... 1 History of Orchid Classification ............................ 4 Objectives of Systematics ................................. 5 Principles of Phylogenetic Systematics ..................... 5 Traditional Orchid Systematics .......................... 6 Phenetics and Orchid Classification ....................... 8 Cladistic Analysis of the Orchidaceae ......................... 9 Character Selection ..................................... 9 Synopsis of Burns-Balogh and Funk Classification ............ 14 Discussion of Characters and Their Aggregation into Transforma- tion Series ........................................ 15 Characters of the Pistil ................................. 15 Characters of the Stamen ............................... 19 Characters of the Pollinarium ........................... 30 Characters Not Used in this Classification .................. 40 Cladogram Construction ................................ 40 Discussion of Characters as Displayed on the Cladogram ......... 41 Discussion of the Cladogram and Resulting Classification ........ 45 Keys to the Subfamilies and Tribes of the Orchidaceae ........... 50 Classification of the Orchidaceae ............................ 53 Conclusion ............................................. 60 Appendix-List of Specimens Examined ...................... 62 Literature Cited ......................................... 70 Platesl-4 .............................................. 72 ... 111 A Phylogenetic Analysis of the Orchidaceae Pamela Burns-Balogh and V.A. Funk Introduction Traditionally, the orchids have been separated posed in the various classifications of the orchids into two major groups (formal or informal) based are poorly defined and subject to constant rear- on the number of anthers: monandrous and non- rangements that appear, at least in some cases, monandrous (Pfitzer, 1888- 1889; Schlechter, to be merely a matter of intuition. 1926). The monandrous orchids (one functional We have identified 68 apomorphies organized stamen) comprise the largest group, with approx- into 42 transformation series. The apomorphies imately 25,000 species, and consist of the were used to construct a cladogram (Figure 1) subfamilies Spiranthoideae, Orchidoideae, Epi- from which a classification was developed. The dendroideae and Vandoideae (for this section of classification presented here recognizes groups the paper all categories are those of Dressler that the cladogram indicates to be natural or 1981; see Table 1). The second group contains monophyletic (sensu Hennig, 1966). The char- orchids that have more than one functional sta- acters used to develop the cladogram were those men. This group is much smaller, with about 200 we found to be consistent within the monophy- species in two subfamilies, the Apostasioideae letic groups they are inferred to delimit (in most and Cypripedioideae. Because of the stamen instances this was the tribal level). The informa- number and partial column development, the tion available on the column structure for mem- orchids with more than one anther (misleadingly bers of the Epidendroideae is incomplete, and referred to as diandrous) are considered to be consequently the resulting classification for that more primitive than the monandrous orchids subfamily is somewhat tentative. The classifica- (e.g., Dressler, 1981). The categories within the tion presented in this paper is compared in Table subfamilies (tribes and subtribes) are based on a 1 with those of Dressler (1981), Garay (1972), variety of characters including vegetative and Schlechter (1970- 1984), Vermeulen (1966), floral features and habit type. As is true with a Dressler and Dodson (1960), and Rasmussen number of the flowering plant families, many of ( 198 3). the groups (subfamilies, tribes and subtribes) pro- ACKNOWLEDGMENTS.-We are grateful to H. Robinson, R.L. Dressler, F.N. Rasmussen, C.J. Pamela Burns-Balogh and V.A. Funk, Department of Botany, National Museum of 'Vatural History, Smithsonian Institution, Humphries, E.W. Greenwood, R. Read, W. Washington, D.C. 20560. Barthlott and five anonymous reviewers for their 1 2 SMITHSONIAN CONTRIBUTIONS TO BOTANY TABLE1 .-Classification systems of Orchidaceae Taxonomist Apostasioideae C ypripedioideae Spiranthoideae Balogh and Funk (1985) Apostasioideae Cypripedioideae Spiranthoideae Neuwiedioideae Cranichideae Prasophylleae Diurideae Dressler and Dodson (1960) Apostasieae Cypripedieae Vermuelen (1 966) Apostasiaceae C ypripediaceae Schlechter (1970-1984) Apostasiaceae Cypripedioideae Cypripedieae Paphiopedileae Phragmipedieae Selenipedieae Garay (1 972) Apostasioideae C ypripedioideae Dressler (198 1) Apostasioideae Cypripedioideae Spiranthoideae Erythrodeae Cranichideae Rasmussen (1983) Apostasiaceae Cypripediaceae NUMBER 61 3 TABLE1.-Continued. Neottioideae Orchidoideae Epidendroideae Vandoideae Neottioideae Orchidoideae Epidendroideae - Neottieae Diseae Arethuseae S.S. Thelymitreae Satyrieae Vanillieae Geoblasteae Orchideae Gastrodieae Pterostylideae Triphoreae Epidendreae Pleurothallis Group Dendrobieae Malaxideae Maxillarieae Vandeae Coelogyneae Orchidoideae - Neottieae Orchideae Epidendreae Epidendroideae Orchidoideae Epidendroideae Contribe Neottieae Contribe Epidendranthae Neottioideae Orchidoideae Epidendroideae Tropideae Satyrieae Podochileae Neottieae Orchideae Arethuseae, Spirantheae Diseae Epidendreae Diurideae Vandoideae Maxillarieae Oncidieae Cataseteae Vandeae Neottioideae Orchidoideae Epidendroideae Epipogieae Orchideae Epidendreae Cranichideae Diseae Vandeae Neottieae Disperideae Orchidoideae Epidendroideae Vandoideae Diseae Epipogieae Cymbidieae Neottieae Vanillieae Vandeae Diurideae Gastrodieae Pol ystachyeae Orchideae Arethuseae Maxillaireae Coelogyneae Malaxideae Cryptarrheneae Epidendreae Cal ypsoeae Neottioideae Orchidoideae Epidendroideae Vandoideae Epipactieae Diurideae Arethuseae Pol ystach yeae Neottieae Orchideae Vanilleae Cymbidieae (= Spiranthoi- Gastrodieae Maxillarieae deae and Epipogieae Vandeae Listerinae) Coelogyneae Malaxideae Epidendreae 4 SMITHSONIAN CONTRIBUTIONS TO BOTANY advice and criticism. We thank H. Robinson for tham (1881) and Schlechter (1926), but his his encouragement. We thank E. Greenwood, groups were basically those of Lindley, although J.B. Comber, and M. Clements for the use of many of the genera had been placed in different some of their color photos and the following groups. Dressler and Dodson (1 960) segregated for sending flowers, pollinaria, photos or draw- the orchids into tribes and subtribes based on ings: P. Bernhardt, M. Clements, J.B. Comber, their level of specialization, but the classification R.L. Dressler, E. Greenwood, E. Hagsater, H. still contained the principal groups devised by Kurzweil, J. McQueen, and F.N. Rasmussen. Lindley. Thanks go to B. Kahn for helping to assemble There are two major conflicts that separate the manuscript. We also thank the National Mu- modern orchid systematists. The first difference seum of Natural History, Smithsonian Institu- of opinion concerns the level of recognition of tion, Washington, D.C., and the University of some of the major taxa within the orchids. One Maryland, College Park, Maryland, for supplying group of workers emphasizes the similarities that SEM time and assistance. Fresh flowers were unite all orchids (partial fusion of the filaments obtained from the US. National Orchid Collec- and style, lack of endosperm, mostly resupinate tion and Marie Selby Botanical Garden. flowers, two inner lateral and one outer median stamen positions) and thinks the Cypripedioideae