Epiphytic herbs. Stems inconspicuous. Leaves coriaceous, fleshy, sheathing at base, sheaths persistent, enclosing stem. Racemes lateral, often elongate and pendulous; peduncle and rachis thick, fleshy, alate-ribbed; bracts small, scale-like. Flowers resupinate, perianth subspreading to spreading; dorsal sepal and petals subequal, free; lateral sepals larger, adnate to back wall of spur; lip adnate to base of column, conical-saccate, more or less laterally compressed, apex with anterior wall thickened into a fleshy projecting midlobe, base with 2 lateral lobes at opening of sac; sac tapering toward bottom, with 2 raised protuberances at top merging into midlobe anteriorly, adnate to lateral lobes posteriorly, without appendages inside; column stout, without distinct foot; clinandrium shallow; anther terminal, operculate, 1-locular or imperfectly 2-locular; pollinia 2, waxy, subglobose to ovoid, neither cleft nor porate, attached by a short rudimentary stipe to viscidium; stigma entire, nearly orbicular; rostellum bifid.
About 10 species, southeast Asia, Australia and the Pacific islands, extending northward to Taiwan and northeast India. One species in Taiwan.