Habit: epiphytic herbs

Stem: sheathing above middle

Leaf: characteristics: sheathing or noding at base

Leaf: position: distichous

Inflorescence: type: raceme

Inflorescence: position: laterally on stem

Floral bract: small

Inflorescence: other characteristics: unbranched

Sepal: concave, lateral sepals spreading or oblique or reflexed or connivent

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

Column: with wing or triangular-falcate or arm-shaped or subulate appendages, with column foot

Pollinia: number: 4

Pollinia: shape: globose or subglobose

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

Viscidium:shape: orbicular or suborbicular