Habit: epiphytic herbs

Stem: noded

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

Leaf: position: distichous

Inflorescence: type: raceme

Inflorescence: position: arising from leaf axil, opposite leaf

Inflorescence: other characteristics: unbranched

Flower: other characteristics: spreading

Petal: shorter or smaller than sepals, similar to sepals

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

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

Pollinia: number: 4

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

Stipe: shape: triangular or subtriangular

Viscidium:shape: sandlelike or subreniform