Rhizome creeping or pendulous; pseudobulbs ovoid to cylindric, bearing 2 leaves
(rarely 1) at apex. Leaf blade oblong to elliptic, thick, petiolate at base.
Inflorescence terminal or lateral to pseudobulbs, several flowered or solitary
flowered; floral bracts caducous. Flowers opening successively. Sepals similar,
concave. Petals linear; lip often concave at base, 3-lobed or rarely unlobed;
lateral lobes erect; callus with longitudinal lamellae. Column winged on both
sides; anther terminal, incumbent; pollinia 4, in 2 pairs, waxy; stigma
concave. Capsules ribbed or narrowly winged.