Robust terrestrial herb 45–70 cm tall; tubers cylindrical, villous.Stem leafy, the lowest 2 ± sheathing, the remainder 7.5–9.5 × 2–3 cm, ovate, acute, usually ± withered by flowering time.Inflorescence densely many-flowered.Pedicel and ovary 3.5–5.5 cm long; bracts 3–3.5 × 1 cm, ovate, acuminate.Flowers green and white.Dorsal sepal 16–18 × 12–13 mm, ovate, acute, very convex; lateral sepals 18–24 mm long, obliquely ovate, rolled lengthways.Petals 2-lobed, both lobes narrowly linear; upper lobe 16–18 mm long, lower lobe 20–25 mm long.Lip 38–45 mm long over all, joined to the stigmatic arms for c. 8 mm at base.Mid-lobe 24–35 mm long; side lobes 18–30 mm long, all lobes filiform.Spur 3–5 cm long, slender, swollen at apex.Stigmatic arms 15–20 mm long; anther canals 8 mm long.