Habit: epiphytic herbs

Stem: sheathing above middle, with scalelike sheath or roots

Leaf: characteristics: sheathing or noding at base, apex notched or acute or obtuse or hooked

Leaf: shape: cylindric, base V-shaped

Inflorescence: type: raceme

Inflorescence: position: laterally on stem

Inflorescence: other characteristics: unbranched

Sepal: lateral sepals spreading or oblique or reflexed or connivent, abaxially keeled

Petal: shorter or smaller than sepals, similar to sepals

Labellum: with sac or spur or auricles at base, 3-lobed

Column: with wing or triangular-falcate or arm-shaped or subulate appendages, without column foot

Rostellum: 2-lobed or beaked

Pollinia: number: 2

Pollinia: shape: globose or subglobose

Pollinia: other characteristics: with caudicle or viscidium, with stipe, with slit

Viscidium: other characteristics: wider than stipe