(Wall. ex Lindl.) Pfitzer, Jahrb. Wiss. Bot. 19: 159 (1888)
Terrestrial herb. Leaves 5–6, ligulate, obtuse at minutely bilobulate apex, up to 32 cm long; 3 cm wide, green, spotted purple at base on underside. Inflorescence 1-flowered; peduncle up to 25 cm long, green, very shortly purple-pubescent; bract elliptic or oblong-elliptic, obtuse, up to 5 cm long, glabrous, purple-spotted at base. Flowers 7–11.6 cm across; dorsal sepal pale green with a white margin, with raised dark maroon spots on inner surface; synsepal pale green, spotted brown; petals yellow-brown, veined red-brown; lip yellow marked with purple-brown; staminode yellow. Dorsal sepal ovate-elliptic to obovate-elliptic, obtuse, 4–7 cm long, 3–4.2 cm wide, apical margins incurved. Synsepal elliptic, subacute or obtuse, 2.2–5 cm long, 1.4–2.5 cm wide. Petals incurved slightly, spathulate, obtuse, 5–6.3 cm long, 1–1.8 cm wide, undulate on upper margin in basal two thirds. Lip 2.4–5 cm long, 1.5–3 cm wide. Staminode obovate, 10 mm long, with purple hairs on surface and with a central raised boss. 2n = 26.