; Orch. Eur. Annot. (Mem. Mus. Hist. Nat. Paris 4: 48: 1818) 26 (1817)
Distribution: boreal and temperate Eurasia and North America, tropics and subtropics, Russia (European part, W- and E-Siberia, Far East), China, south to tropical Asia and New Guinea. Many authors accept spinoff genera like Blephariglottis, Diphylax, Limnorchis, Fimbriella, Lysiella, Pseudodiphryllum, Piperia, etc. We take a conservative approach and list the genus in a broad sense. Species delimitation especially in E-Asia is quite controversial.
= Blephariglottis Raf.; Fl. Tellur. 2: 38 (1836)
= Conopsidium Wallr.; Linnaea 14: 147 (1840)
= Denslovia Rydb.; Brittonia 1: 85 (1931)
= Diphylax Hook.f.; Hook., Ic. pl. 19: t. 1865 (1889)
= Diplanthera Raf.; Herb. Raf. 73 (1833):
= Fimbriella Farw. ex Butzin; Willdenowia 11(2): 323 (1981)
= Gymnadeniopsis Rydb.; Britton, Man. Fl. N. U. S. 293 (1901)
= Limnorchis Rydb.; Mem. N. Y. Bot. Gard. 1: 104 (1900)
= Lysias Salisb.; Trans. Hort. Soc. 1: 288 (1812)
= Lysiella Rydb.; Mem. N. Y. Bot. Gard. 1: 104 (1900)
= Mecosa Blume; Bijdr. Fl. Ned. Ind. 403, t. 1 (1825)
= Perularia Lindl.; Edwards´s Bot. Reg. sub t. 1701 (1835)
= Piperia Rydb.; Bull. Torrey Bot. Club 269 (1901)
= Pseudodiphryllum Nevski; Komarov, Fl. URSS 4: 649, 752 (1935)
= Sieberia Spreng.; Anleit. Kenntn. Gew., ed. 2, 2(1): 282 (1817)
= Smithorchis Tang & F.T.Wang; Bull. Fan Mem. Inst. Biol., Peiping, Bot. Ser. 7: 139 (1936)
= Tulotis Raf.; Herb. Raf. 70 (1833), et Fl. Tellur. 2: 37 (1886)
= xBlepharopsis Efimov; Novosti Sist. Vyssh. Rast. 40: 48 (2008 publ. 2009)
= xPlatanthopsis P.M.Br.; N. Amer. Native Orchid J. 8: 37 (2002)
