Epiphytic, lithophytic, or terrestrial
herbs. Pseudobulbs ovoid, ellipsoid, or spindle-shaped, rarely absent. Leaves
several to many, distichous, usually lorate or linear. Inflorescence arising
from base of pseudobulb, erect to pendulous; rachis several to many flowered;
floral bracts persistent. Flowers large or medium-sized. Sepals and petals
free, subsimilar; lip free or basally fused, usually 3-lobed; lamellae sometimes
inflated toward apex. Column rather long, arcuate; pollinia 2, or 4, waxy.