Description from Flora of China
Herbs, epiphytic or lithophytic, monopodial, usually stemless and leafless. Roots green, photosynthetic, flat, scabrid. Inflorescence often pendulous, racemose, hairy or glabrous. Flowers ephemeral. Sepals and petals subequal; lateral sepals and petals often adnate to column foot. Lip ± clawed, hinged to apex of column foot, pouched or spurred, 3-lobed; lateral lobes erect, large; mid-lobe small; disk with a fingerlike callus, hirsute-pubescent. Column subterete, short, foot long; clinandrium shallow; stigma deep-set; rostellum deflexed, bifid; anther cap with 2 long filiform setae; pollinia 4, in 2 closely appressed, unequal, sessile pairs; stipe sublinear.
About ten species: from the Indian subcontinent through SE Asia to Australia; three species (all endemic) in China.
(Authors: Chen Xinqi (陈心启 Chen Sing-chi); Jeffrey J. Wood)