comprising more than 10,000 species in about 90 to 100 genera. Most are tropical epiphytes (usually with pseudobulbs), but some are terrestrials and even a few are myco-heterotrophs. All show a unique development of the single anther: it is incumbent, meaning that it forms a right angle with the column axis or pointed backward in many genera. Most have hard pollinia, i.e. a mass of waxy pollen or of coherent pollen grains; pollinia with caudicle and viscidium or without; stigma entire or 3-lobed; rostellum present; 1-locular ovary; leaves: distichous or spiraling Tribe Arethuseae Over 500 species. Subtribe Arethusinae Arethusa L. × Elearethusa × Elecalthusa Eleorchis F.Maek. × Elepogon Subtribe Bletiinae Ancistrochilus Rolfe Anthogonium Wall. ex Lindl. Cephalantheropsis Guillaumin Eriodes Rolfe, included Neotainiopsis Bennet & Raizada, Tainiopsis Schltr. Hancockia Rolfe Hexalectris Raf. Ipsea Lindl. Mischobulbum Schltr., included Mischobulbon Schltr. (orth. var.) Nephelaphyllum Blume Pachystoma Blume, included Apaturia Lindl., Pachychilus Blume and Pachystylis Blume Alliance Arundina Arundina Rich. Alliance Calopogon Calopogon R.Br., included Cathea Salisb., Helleborine Kuntze Alliance Calanthe Acanthophippium Blume, included Acanthophippium Blume (orth. var.) Bletia Ruiz & Pav., included Anthogyas Raf., Bletiana Raf., Crybe Lindl., Gyas Salisb., Regnellia Barb. Rodr., Thiebautia Colla Bletilla Rchb.f., included Jimensia Raf., Polytoma Lour. ex Gomes Calanthe R.Br., included Alismorkis Thouars, Amblyglottis Blume, Aulostylis Schltr., Calanthidum Pfitzer, Centrosia A.Rich., Centrosis Thouars, Cytheris Lindl., Ghiesbreghtia A.Rich. & Galeotti, Limatodes Blume, Paracalanthe Kudô, Preptanthe Rchb.f., Styloglossum Breda, Sylvalismis Thouars Phaius Lour., included Cyanorchis Thouars, Gastorchis Thouars, Gastrorchis Schltr., Hecabe Raf., Pachyne Salisb., Pesomeria Lindl., Tankervillia Link Spathoglottis Blume, included Paxtonia Lindl. Alliance Coelia Coelia Lindl., included Bothriochilus Lem. Alliance Chysis Chysis Lindl., included Thorvaldsenia Liebm. Alliance Plocoglottis Plocoglottis Blume Alliance Tainia Tainia Blume, included Ania Lindl., Ascotainia Ridl., Mitopetalum Blume Subtribe Sobraliinae Sobralia Ruiz & Pav., included Cyathoglottis Poepp. & Endl., Fregea Rchb.f., Lindsayella Ames & C.Schweinf. Subtribe Thuniinae Thunia Rchb.f. Tribe Calypsoeae Aplectrum (Nutt.) Torr. Calypso, included Calypsodium Link, Cytherea Salisb., Norna Wahlenb., Orchidium Sw. Tipularia Nutt., included Anthericlis Raf., Plecturus Raf. Wullschlaegelia Rchb.f. Tribe Cryptarrheneae Cryptarrhena R.Br., included Orchidofunckia A.Rich. & Galeotti Tribe Coelogyneae Over 400 species Subtribe Adrorhizinae Adrorhizon Hook.f. Subtribe Coelogyninae Coelogyne Lindl., included Bolborchis Lindl., Hologyne Pfitzer, Ptychogyne Pfitzer Dendrochilum Blume, included Acoridium Nees & Meyen, Platyclinis Benth. Pleione D.Don Tribe Epidendreae Cosmopolitan; largest tribe of this subfamily, with over 8,000 species Subtribe Glomerinae Agrostophyllum Blume Earina Lindl. Glomera Blume, included Ischnocentrum Schltr.,Sepalosiphon Schltr. Subtribe Laeliinae: over 1400 species, mostly tropical American