Plant robust, up to 1 m tall. Tubers large, spindle-shaped. Stem stout, leafy, above densely covered with cucullate, large sheaths, passing into the bracts. Leaves 4-5, crowded below the middle of stem, elliptic, acute, up to 10(-15) x 5(-6) cm. Inflorescence 3-5-flowered. Bracts cucullate, exceeding ovary. Flowers very large, up to 7 cm in diam., white, ± tinged with greenish, somewhat waxy, strongly fragrant in the evening. Dorsal sepal broadly obtriangular, up to 4.5 x 4.5 cm; the lateral sepals spreading, obliquely-oblong, 4 x 2.2 cm. Petals linear, fleshy, 3.5 x 0.3 cm. Labellum up to 4 x 7 cm, fleshy, 3-lobed; mid-lobe linear-lanceolate to ligu¬late, 3.5 x 0.4-0.9 cm, side-lobes fan-shaped, deeply laciniate, in front 3-3.5 cm broad. Spur about twice as long as ovary, 8-11(-13) cm long, rather slender. Column up to 1-1.5 cm high. Ovary elongate ± 5 cm long.