Epiphytic herbs with fleshy, fusiform or clavate, often more or less pendent, pseudobulbous stems. Leaves broadly plicate, the sheathing bases enveloping the pseudobulbs, the leaf blades becoming deciduous at the end of the current season's growth. Inflorescences usually solitary, produced from the axils of one of the lower bracts of the flush of leafy new growth, the scape terminating above in a short, few-flowered raceme. Flowers relatively large and conspicuous. Sepals subequal, free, spreading, the dorsal sepal erect, the broader lateral sepals oblique and adnate to the foot of the column. Petals free, subequal to the sepals, but usually narrower. Lip fleshy, 3-lobed, the lateral lobes rounded or falcate, erect in natural position, or converging over the column, the mid-lobe erect or reflexed, often more or less 2-lobed or emarginate; disk with 3 to 5 longitudinal fleshy crests. Column short, erect, arcuate, broadly winged or roughly triangular in cross-section, produced at the base into a foot. Anther subrotund, operculate, in-cumbent; pollinia 8, waxy, oblong-ovoid, 4 in each cell of the anther.