A terrestrial herb 60–120 cm. tall. Perennating organs underground, tuberous, irregularly conical, 4–6 cm. long, 2.5–4 cm. diameter, orange, separated by a stout rhizome up to 7 mm. diameter and 2 cm. long; roots 1.2–3 mm. diameter, white. Leaves fleshy, not plicate, 3–6, in a fan, 30–65 cm. long, 0.6–2.2 cm. wide, basal one sheathing. Inflorescence produced before the leaves, laxly many-flowered; peduncle stout, purplish, bearing 4–5 sheaths mostly near base, uppermost lanceolate; rhachis 11–29 cm. long; bracts lanceolate, acuminate, 4–14 mm. long. Flowers variable in size; sepals greenish; petals yellow; lip yellow with red veins on side lobes; column pale greenish; pedicel and ovary 12–19 mm. long. Dorsal sepal reflexed, elliptic, apiculate, 5–11 mm. long, 2–4 mm. wide; lateral sepals similar. Petals spreading, elliptic-ovate, obtuse, 11–18 mm. long, 8–15 mm. wide. Lip difficult to flatten, 3-lobed, 12–16 mm. long, 10–14 mm. wide; side lobes erect but reflexed above, obscurely rounded; mid-lobe convex, elliptic, subacute, 10–13 mm. long, 8–12 mm. wide; callus of 3–5 low fleshy rugulose ridges on mid-lobe; spur shortly conical, 1–3 mm. long. Column 4–6 mm. long. Fruit pendent, 3.5 cm. long. Pl. 3. Fig. 108/1–12, p. 475.