Habit: epiphytic herbs

Stem: branched, unbranched, tufted or separate, with leaves, noded

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

Leaf: position: alternate

Leaf: shape: cylindric

Inflorescence: type: raceme, umbel

Flower: other characteristics: spreading, pendulous

Sepal: free or similar, lateral sepals adnate to column foot or labellum forming a mentum

Petal: narrower than sepals or as long as dorsal sepal, broader than sepals

Labellum: with sac or spur or auricles at base, 3-lobed, not lobed

Column: with column foot

Pollinia: number: 4

Pollinia: shape: subclavate or ovate