Epiphytic herbs. Roots elongate, flattened. Stems short, enclosed by leaf sheaths. Leaves few, closely arranged, fleshy, distichous, coriaceous, articulated with sheath at base. Racemes lateral, erect or ascending, branched or not; peduncle slender, much longer than leaves; bracts much smaller than pedicel and ovary. Flowers fairly large, long-lasting; sepals similar, spreading; petals usually wider than sepals, often clawed at base; lip clawed or sessile, continuous with short foot of cloumn, 3-lobed, lateral lobes erect, midlobe spreading, sometimes with 2 slender tails at apex; disc with one or more appendages or callosities between lateral lobes or at base of midlobe; clinandrium shallow; anther terminal, operculate; pollinia 2, ovoid or globose, unequally cleft, attached by long stipes to viscidium, stipes narrow at base, widening upwards; stigma entire, concave; rostellum well developed, apex bifid.
About 40 species, from the tropical Himalaya, Malaysia, the Philippines and Indonesia to Australia and Papua New Guinea. Two species in Taiwan.