Glabrous terrestrial herb 50–80 cm high. Pseudobulbs 2–4 × 1.5–2.5 cm, conical to ovoid, 5-angled, usually 2-leaved.Leaves 12–21 × 1–1.5 cm, linear to narrowly lanceolate, tapering to a petiolate base 3–10 cm long, coriaceous, grey-green with blue-grey or whitish-grey blotches. Inflorescence simple, 22–60 cm tall, laxly 9–20-flowered, the scape with c. 12 linear bracts 1–2 cm long. Pedicel and ovary 12–25 mm long, slender; bracts 5–15 mm long, linear. Sepals and petals dark olive-green or yellow-green, veined with purple; lip yellow, cream or pale green with purple or red nerves and a central yellow patch; crests lilac; spur orange or green. Sepals 12–20 × 2.5–4 mm, spathulate, apiculate. Petals 7–10 × 4–7 mm, oblong-elliptic or ovate-elliptic, apiculate, narrowed at base. Lip 12–16 mm long, 12–18 mm wide, appearing 4-lobed (3-lobed with the mid-lobe 2-lobed); each lobe of mid-lobe suborbicular or broadly oblong; side lobes erect, subquadrate; base of lip with a callus formed of 2 raised, oblong lobes which extend to the apical sinus as 2 low, minutely papillose keels, often with a third median keel; spur 3–6 mm long, stout, decurved, cylindrical but often slightly swollen in the middle, the apex blunt. Column erect, 4–5 mm long with a short foot c. 2 mm long.