A large robust epiphyte or lithophyte with an erect stem 60–100 cm. long, 1.5–2 cm. in diameter; roots thick, fleshy, like boot-laces, 3.5–5 mm. in diameter. Leaves 6–10 or more, distichous, fleshy-coriaceous, obovate-ligulate, unequally roundly bilobed at the apex, 16–50(–70) cm. long, 2.9–7 cm. wide. Inflorescences suberect or ascending, 8–20-flowered, 30–75 cm. long; peduncle stout, 12–29 cm. long, bearing 1–3 well-spaced sheaths along length; bracts amplexicaul, broadly ovate, obtuse, 0.9–1.5 cm. long, dark brown. Flowers with a white lip, yellow-green at the mouth of the spur and with green sepals, petals and column, pleasantly scented at night; pedicel and ovary 16–18 mm. long, with the ovary twisted through 180°. Sepals reflexed, linear-lanceolate, acuminate, 3.3–4.5 cm. long, 5–7(–10) mm. wide. Petals linear-lanceolate, acuminate, 3.2–4.2(–4.5) cm. long, 5–7 mm. wide. Lip erect, transversely oblong to broadly ovate, (2–)2.4–3(–4.5) cm. long, 2.8–4.2 cm. wide, with a terminal apicule 5–7 mm. long; callus an entire ridge tapering from the base to the apex in the middle of the lip; spur cylindrical, pendent, 4–5.8(–7) cm. long. Column fleshy, 5 mm. long, green.
Voy. 1: 359, t. 19 (1804); Senghas & Cribb in Die Orchidee 30(1): CXXI–CXXII (1979). Type: Réunion, Bory de St.-Vincent (P, holo.)