Terrestrial herb 1–2 m tall.Perennating organ a fleshy, subterranean rhizome c. 1 cm in diameter; roots 1.5 mm in diameter, white.Leaves 4, up to 120 × 5–10 cm, erect, lanceolate, acuminate, plicate, with a long petiole.Inflorescence densely many-flowered; scape with 3 sheaths.Pedicel and ovary 18–20 mm long; bracts 10–30 mm long, reflexed, linear, aristate.Flowers not opening widely; sepals greenish-yellow, petals and lip reddish-brown or red-purple, occasionally white with a purple disk on the lip.Dorsal sepal 18–20 × 4–5 mm, oblong-lanceolate, subacute; lateral sepals slightly longer and wider.Petals 15–19 × 3–5 mm, oblong-ligulate.Lip 14–19 × 8–12 mm, with a saccate base, 3-lobed in the apical half; side lobes rounded, mid-lobe 5–6 × 8 mm, the edges undulate.Lip with a callus of 2 flap-like ridges in the middle, and with papillae on the 5 central veins of the mid-lobe.Column 7–10 mm long; foot 4 mm long.Fruit 3 cm long, pendent.