A lithophytic herb. Leaves 4–6, narrowly oblong-elliptic to oblong-ligulate, obliquely unequally roundly bilobed at apex, up to 30 cm long, 9.8 cm wide, green, purple-flushed at base on undersurface, ciliate on basal margins. Inflorescence arcuate, up to 60 cm long, many-flowered; peduncle erect, 18–34 cm long, purple, finely white-pubescent; rhachis zigzag, white-pubescent; bracts conduplicate, elliptic, rounded, lowest 3–3.5 cm long, 2.6–2.8 cm wide, green, ciliate, up to 2 cm apart on rhachis. Flowers up to 32, borne successively, one or two open at a time, 8–10 cm across; dorsal sepal lime-green, yellow-green or white, flushed green or yellow in lower half, deep purple-veined; synsepal yellow-green with purple veins; petals yellow or pale yellow, spotted and streaked with dark maroon; lip pink with a white rim, spotted purple; staminode green, heavily flushed dark maroon; pedicel and ovary 4–5 cm long, yellow marked with purple on ribs and at base, pubescent. Dorsal sepal subcircularelliptic, obtuse, 2.8–3.9 cm long, 2.6–4 cm wide, with undulate margins, long-pubescent on outer surface. Synsepal elliptic, truncate or rounded, 2.8–4 cm long, 2–2.6 cm wide. Petals horizontal, slightly recurved, ligulate, obtuse, 4–5.2 cm long, 0.75–1.2 cm wide, twice-twisted, ciliate. Lip rather bulbously inflated, 3.9–5.4 cm long, 1.9–2.6 cm wide, with a retrorse apical mucro; side-lobes broadly rounded at apex. Staminode convex, shortly trullate-deltoid, 8–9 mm long, 7–7.5 mm wide, pubescent in basal half. 2n = 30.