Epiphytic with homoblastic pseudobulbs, rarely terrestrial, leafless or generally epiphytic leafy plants with creeping, branched and fleshy rhizomes. Leaves long, coriaceous. Scape lateral, loosely sheathed, with erect or pendulous, several to many-flowered raceme. Flowers resupinate, usually large and showy. Sepals and petals subequal, erect or spreading. Labellum sessile at base of column, 3-lobed or ± entire, side lobes embracing the column; mid-lobe recurved, disk usually with 2 keels. Column long, without foot; anther terminal, incumbent, pollinia 2, waxy, sulcate, with short, broad stipe; stigma entire.
c. 40 species in tropical and subtropical Asia, Malaysia, New Guinea and Australia. 1 terrestrial leafless species in Pakistan.