Herbs, terrestrial or rarely epiphytic. Rhizome creeping, several noded, fleshy; roots fibrous, villous, arising from rhizome nodes. Stem erect, glabrous, with a few tubular sheaths at base, leafy. Leaves usually crowded at stem apex, green-red, midvein often white, lanceolate, ovate, or elliptic, oblique, apex acute, with a petiole-like base dilating into tubular amplexicaul sheath. Inflorescence erect, terminal, racemose, pubescent; peduncle with a few scattered sheathing bracts; rachis laxly to subdensely few to many flowered; floral bracts sparsely pubescent. Flowers not opening widely, obliquely resupinate or not resupinate; ovary and pedicel not twisted, glabrous to sparsely pubescent. Sepals free, similar, ovate-elliptic, outer surface glabrous to sparsely pubescent. Petals connivent with dorsal sepal and forming a hood, often broadly dilated, membranous; lip adnate to ventral margin of column, 2-partite or with a short mesochile and 3-partite; hypochile saccate, with a low, longitudinal carina along midvein forming a large, raised bicarinate callus toward apex of hypochile, and with 1 fleshy, undivided callus on either side near base; exterior of hypochile with fleshy flanges; mesochile (when present) short, margin involute; epichile linear, quadrate or transversely dilated, simple or 2-lobed. Column short, abruptly dilated apically, with 2 large, parallel wings; anther ovoid, 2-locular; pollinia 2, clavate, attached to a solitary, small, ovate viscidium; rostellum deltoid, short, broad, remnant shortly bifid; stigma lobes 2, separate, placed laterally at column apex, convex. Capsule erect.

About 25 species: from the Himalayas and NE India, across S and SE China to S Japan, and throughout SE Asia to New Guinea and the SW Pacific islands; four species (one endemic) in China.