Epiphytic herbs. Stems up to 30 cm long, pendent or ascending, simple or sometimes branching, with several to many nodes. Leaves many, distichously arranged, glabrous, dorsiventrally flattened, semi-terete or terete, articulate to a sheathing base, deciduous, duplicate. Inflorescence lateral, racemose or paniculate, many-flowered. Flowers resupinate, usually not opening widely, usually white or red-purple. Sepals similar, free, often dorsally carinate. Petals free, smaller than sepals. Labellum rigidly adnate to base of column, about as long as petals or longer, trilobed, spurred at base, side lobes erect, midlobe slightly larger, often spatulate; spur usually parallel to ovary, lacking interior calli, sometimes with a longitudinal dividing wall inside near apex. Column without foot; pollinia four, arranged as two pairs, waxy, about equal, flat-globular or semi-globular, solid, attached by a common stipe to a narrowly elliptic to ovate viscidium; stigma at base of column; rostellum pointed, geniculate.