320 Orchidaceae 



16B. Lip concave at base, sometimes loosely enveloping the column; leaves alternate. 



18A. Lip divided by a constriction into an upper and lower portion; leaves if present more or less plicate. 



19A. Plant saprophytic, without green leaves 15. Aphyllorchis 



19B. Plant not saprophytic, with green parts. 



20A. Lip with a chin at base, distinctly jointed between the upper and lower portions 16. Cephalanthera 



2 OB. Lip without a distinct chin at base, not jointed between the upper and lower portions 17. Epipactis 



18B. Lip not divided into an upper and lower portion; leaves if present flat, not plicate. 



21 A. Plant with a single green cauline leaf; flowers solitary, with a green bract at base 18. Pogonia 



21B. Plant saprophytic, without green parts; flowers more than 1. 



22A. Plant with branching stem; perianth without a calyculus at base 19. Galeola 



22B. Plant small with unbranched stem; perianth with 3 small calyculae at base 20. Lecanorchis 



15B. Plant with corms or fleshy to coralloid rhizomes. 



23A. Leaves jointed at base 21. Bletilla 



23B. Leaves not jointed, soft, or reduced to scales in saprophytic plants. 

 24A. Perianth-segments not connate. 



25A. Leaf solitary, radical, petiolate, broad; flowers before the leaves (solitary in our species) 22. Nervilia 



25B. Leaves cauline, reduced to scales or sheaths. 



26A. Lip spurred; column without an appendage 23. Epipogium 



26B. Lip spurless; column with a tooth at base 25. Stigmatodactylus 



24B. Perianth-segments connate; plant saprophytic, without green leaves 26. Gastrodia 



13B. Anthers more or less erect; rostellum erect or nearly so. 

 27A. Leaves flat, not plicate, thinnish to more or less fleshy. 



28A. Stems erect, the roots fasciculate at base 27. Spiranthes 



28B. Stems creeping or decumbent at base and rooting at intervals. 



29A. Flowers with a definite oblong stipe between the pollinia and the viscid disc of the rostellum on the column. 



30A. Sepals free; column without distinct prolongations 34. Zeuxine 



30B. Sepals connate to the middle; column with 2 upright narrow arms 30. Cheirostylis 



29B. Flowers without a definite narrow stipe between the pollinia and the viscid disc of the rostellum, on the column. 

 31 A. Sepals more or less connate, often up to the middle. 



32A. Lip ventricose at base, spurless 33. Myrmechis 



32B. Lip with a bilobulate spur 31. Vexilhb'mm 



31B. Sepals free or nearly so. 



33A. Lip with a dentate or fimbriate claw 32. Odontochilus 



33B. Lip without a definite claw. 



34A. Stigma simple; base of lip with hairs 28. Goodyera 



34B. Stigma bilobed; base of lip variously callose 29. Hetaeria 



27B. Leaves plicate, thin, many-nerved; stems slender, but firm 35. Tropidia 



12B. Pollinia waxy or cartilaginous; anther easily detached; inflorescence terminal or lateral. 

 35A. Inflorescence terminal. 



36A. Lip slipper-shaped, with bifid or obtuse spur toward the apex. 



37A. Leaf solitary, radical; flowers solitary and terminal 36. Calypso 



37B. Leaves reduced to scales; flowers racemose, fleshy; saprophytic herbs without green parts 24. Yoania 



36B. Lip not slipper-shaped. 



38A. Leaves distichous, equitant, evergreen; flowers minute, numerous, in spikes; lip not spurred 37. Oberonia 



38B. Leaves dorsi-ventrally flattened. 



39A. Lip spurred 38. Tipularia 



39B. Lip not spurred. 



40A. Lip rather similar to the sepals and petals 39. Didiciea 



40B. Lip different from sepals and petals. 



41A. Rhizomes slender, elongate, not thickened 40. Ephippianthus 



41B. Rhizomes short, thickened. 



42 A. Flowers small; column very short. 



43A. Anthers deciduous 41. Microstylis 



43B. Anthers not deciduous, persistent, withering in place 42. Malaxis 



42B. Flowers small to large; column elongate. 



44A. Flowers 1 (rarely paired) ; leaves solitary 43. Eleorchis 



44B. Flowers in racemes, smaller; leaves more than 1 44. Liparis 



35B. Inflorescence lateral. 



45A. Leaves convolute in bud. 



46A. Pollinia 4 or 8, with caudicle but without stipe; leaves jointed or not jointed at base. 

 47A. Leaves not jointed at base. 



48A. Lip nearly free from the column 45. Phajus 



48B. Lip adnate to the column at base 46. Calanthe 



47B. Leaves jointed at base 47. Tainia 



46B. Pollinia 2 or 4, without a caudicle; leaves jointed at base. 

 49A. Lip saccate or spurred at base. 



50A. Lip broad; perianth parts spreading 48. Eulophia 



50B. Lip narrow, linear; perianth parts subparallel 49. Cremastra 



49B. Lip not spurred at base. 



