Plants 12-73(-100) cm. Stems swollen at base (rarely attenuate), 2-12 mm diam. distal to leaves; bracts (4-)12-37. Leaves prostrate; blade 6-20(-38) × 1-9 cm. Inflorescences usually densely flowered, cylindric, 2.5-40 cm; rachis shorter than peduncle; bracts 6-24 mm. Flowers mostly white, fragrance strong at night; sepals white with green midvein, 3-7 × 1.6-3 mm; dorsal sepal ovate to oblong; lateral sepals usually widespreading, ovate-elliptic to oblong-lanceolate; petals spreading, recurved, straight, ovate to oblong-lanceolate, (3-)4-6 × 1.5-2.5 mm; lip recurved, pale greenish to white, triangular-lanceolate to lanceolate, 2.5-7 × 1.5-3.5 mm; spur usually deflexed, curved, (3-)7-14 mm; viscidia 0.4-1 × 0.15-0.5 mm; rostellum blunt. Capsules 5-12 mm. Seeds cinnamon brown. 2n = 42.

[Key to subspecies contained in key to species.-Ed.]