Plants lithophytic or terrestrial. Leaves 5 or 6, distichous; blade abaxially usually without purple marks at base, adaxially uniformly dark green, lorate or linear, 23-44 × 1.4-2.2 cm, leathery, usually acuminate and tridenticulate at apex. 

Scape suberect or arching, usually terminating in a solitary flower; peduncle brown-purple, 13-24(-30) cm, densely long hairy; floral bract ovate, 8-15 mm, abaxially densely hairy, ciliate; pedicel and ovary 6-8.5 cm, pubescent. Flower 8-16 cm in diam., initially dorsal sepal curving forward and petals not undulate at margins and then dorsal sepal erect and petals elongating and undulate along basal margin; dorsal sepal and synsepal dark brown, with yellowish or greenish margin; petals yellowish, with dense purple-brown speckles in basal half and purplish rose in apical half; lip yellowish to greenish, with dense brownish or purplish rose speckles; staminode dark brown with narrow yellowish margin and 2 large whitish spots and a yellowish blotch centrally. Dorsal sepal broadly ovate or ovate-elliptic, 3.7-4.4 × 2.6-3.5 cm, abaxially sparsely pubescent mainly on veins, ciliate, undulate at margin, obtuse or emarginate at apex; synsepal similar to dorsal sepal, slightly narrower. Petals often slightly twisted toward apex, spatulate, (4-)6-8 × 1.5-2.5 cm, both surfaces slightly or scarcely puberulent, basal half undulate at margin, ciliate, rounded or subtruncate at apex; lip helmet-shaped, 3-5 cm; pouch 2.5-3(-3.5) × 1.5-2.5 cm, slightly puberulent outside particularly along margin and veins. Staminode subsquare, 8-10 × 8-10 mm, adaxially convex, apex obtuse. Fl. Apr-May. 2n = 26.