Flowers resupinate or not. Lip frequently 3-lobed, usually spurred, or at least, saccate basally. Spur entrance below gynostemium.
Column part absent. Stigma variable in size and shape. Rostellum joined basally with the fertile part of the stigma, 3-lobed, primarily with the midlobe pleated, shelf-like, secondarily furculate, sometimes the midlobe greatly reduced and both lat lobes stalked. Occasionally rostellum produces sac-like structures, bursiculae, covering viscidia. Viscidia double, secondarily joined together, detachable.
Anther erect to bent back, both locules well separated by usually wide and often massive connective. Auricles well developed in most genera, but occasionally reduced.
Largest tribe, containing more than 1,700 species.
Bibliography and References:
Kashyap SK, Mehra PN. 1983 Cytological investigations on West-Himalayan orchids. Tribe: Orchideae: 1. The genus Habenaria Willd. Cytologia (Japan), 48. (3): 633-646 (1983)
Kashyap SK, Mehra PN. 1983 Cytological investigations on West-Himalayan orchids tribe: Orchideae: 2. Several genera. Cytologia (Japan) 48. (3): 647-657 (1983)
Luo YB. 2004 Cytological studies on some representative species of the tribe Orchideae (Orchidaceae) from China. Bot. J. Linn. Soc. 145. (2): 231-238 (2004)
Tikhonova MN. 1983 About the nature of the underground organs of some representatives of the tribe Orchideae. Bot. Zh. SSSR. 68. 648-52.