Herbs, terrestrial [rarely epiphytic], cespitose. Stems modified into corms [pseudobulbs], concealed by leaf sheaths. Leaves usually caducous, 1-several [sometimes much reduced, scalelike], basal, distichous, imbricate near base, clustered distally, nearly [distinctly] petiolate; blade plicate, not articulate with leaf sheaths, leathery. Inflorescences lateral, arising from base of corm [pseudobulb], racemes [rarely paniculate], erect. Flowers resupinate, showy; sepals and petals distinct [lateral sepals sometimes connate at base] and free, sepals erect to spreading; lip adnate or articulate to column foot, concave, saccate [sometimes spurred], 3-lobed; disc with erect lamellae; column erect, slightly arcuate, semiterete, long, more than 10 mm [short], basally produced into conspicuous foot, with shallow lateral wings distally; anther terminal, incumbent, 1-locular, operculate, 2-lobed at apex [entire]; pollinarium with 2 pollinia, yellow, nearly triangular to nearly circular, sulcate, cartilaginous; stipe short, inconspicuous [conspicuous, ligulate], viscidium semicircular [semilunar]. Fruits capsules, pendent when mature.