Herbs, terrestrial, sympodial. Roots fleshy, villous. Stems succulent, glabrous. Leaves cauline, sessile [petiolate], not articulate; blade convolute, conduplicate, often membranous. Inflorescences terminal, dense spikes [racemes]; flowers spirally arranged; floral bracts mostly longer than flowers, membranaceous, scarious. Flowers few-many, resupinate, white with yellow lip, small, scarcely opening; sepals subequal; dorsal sepal erect, connivent with petals, forming hood over column; lateral sepals distinct and free, enclosing base of lip; lip pandurate, broadly rounded, margins entire, apex slightly broadened to winglike; column short; anther abaxial, 2-chambered, membranous; pollinia 2, sometimes 2-lobed, pyriform, sectile, caudicles present or absent; stigmas 2, on either side of column, convex; rostellum large, deeply divided. Fruits capsules, erect, ovoid [subglobose].