Plants epiphytic. Leaves 5-7, distichous; blade pale green or yellowish green abaxially, uniformly dark green adaxially, narrowly elliptic, (8-)20-40 × 2.7-3.5 cm, thickly leathery, rounded and slightly unequally bilobulate at apex. 

Scape arching or suberect, 28-35 cm; peduncle green, densely white pubescent; raceme 3-5-flowered; floral bracts green, broadly ovate-elliptic, conduplicate, 2.5-3 cm, glabrous; pedicel and ovary 3-4 cm, densely white pubescent. Flowers 8-10 cm in diam., deciduous after pollination; dorsal sepal and synsepal yellowish green to greenish with darker veins; petals pale yellow-green and spotted with blackish maroon in basal half, dark maroon along margin and in apical half; lip yellowish green or green, sometimes flushed purplish, with darker veins; staminode whitish with a dark green center. Dorsal sepal elliptic, 3-5 × 2-3 cm, adaxially puberulent toward base and apex, basal margin recurved, acute at apex; synsepal similar to dorsal sepal, slightly smaller, obtuse at apex. Petals decurved-pendulous, twisted particularly in apical half, linear-lanceolate or linear-tapering, 7-9.5 × 0.6-0.8(-1) cm, margin undulate in basal half, apex rounded, both surfaces ± puberulent, abaxially with several maroon spots or warts near or along lower or rarely also upper margin in basal half; warts usually with a cluster of hairs; lip helmet-shaped, 3-4 cm; pouch 1.5-2.5 × 1.5-2 cm. Staminode obcordate or obovate, 10-13 × 7-8 mm, with a deep sinus at apex and a small umbo near base, slightly puberulent at adaxial base. Fl. Jun-Jul. 2n = 26.