Plants 20-40 cm tall, with ovate-oblong, sessile tuberoids. Stem slender, leafy. Leaves 2-3(-4), oblong, up to 14 x 4.5 cm, terminating into a sharp point. Inflorescence lax, up to 15 cm long. Lower bracts ovate lanceolate, acuminate, exceeding ovary, the upper ± equalling ovary. Flowers green. Sepals dark green, minutely ciliolate at margins; the dorsal broadly ovate, concave, 4-5 x 4 mm; the lateral sepals ovate or oblong, 5-7 x 3.5-4 mm, spreading or deflexed. Petals green or yellowish-green, glabrous, spreading, obliquely triangular, curved inwards, 7 mm long, with c.3 mm broad base. Labellum green, sometimes yellowish-green, somewhat fleshy, entire, linear, with short claw, then ± knee-like bent downwards, 6-9 mm long. Spur slender, 10-15 mm long, widened at the base, deflexed, parallel to ovary, sometimes turned outwards, equalling or slightly exceeding the ovary in length. Column 2 mm high; anther-canals short, curved forwards: stigmatic processes oblong.