Habit: epiphytic herbs

Stem: noded, with scalelike sheath or roots

Leaf: characteristics: sheathing or noding at base, base clasping

Leaf: position: distichous

Inflorescence: position: laterally on stem

Inflorescence: other characteristics: unbranched

Flower: other characteristics: spreading

Petal: shorter or smaller than sepals

Labellum: with sac or spur or auricles at base, adnate to column

Column: without column foot

Pollinia: number: 2, 4

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

Viscidium: other characteristics: wider than stipe