Terrestrial herb 25–80 cm tall; tubers to 5 × 2.5 cm, ovoid or ellipsoid.Stem leafy.Leaves 7–11, the lowermost 1–2 sheath-like, the mid-stem leaves suberect, the largest 7–15 × 2–4.5 cm, ovate or lanceolate; the uppermost grading into the bracts.Inflorescence 4–20 × 7–13 cm, laxly or fairly densely few- to several-flowered; bracts to 6 cm long.Flowers greenish or green with white lip, sometimes sweetly scented.[Williamson & Gassner's field notes say that the woodland form is heavily scented, the grassland form is not].Pedicel and ovary 4.5–7.5 cm long, curved up.Dorsal sepal erect, 14–20 × 6–10 mm, elliptic, convex; lateral sepals deflexed, 18–24 × 8–15 mm, rolled lengthwise.Petals 2-lobed almost to base, upper lobe 15–20 × 0.5 mm, filiform, adnate to dorsal sepal; lower lobe curving up, 20–40 × 1–3 mm, horn-like, rather fleshy.Lip 3-lobed to c. 2 mm from base; mid-lobe deflexed, 16–35 × 1 mm, linear; side lobes 6–12 × 1–3 mm, lanceolate, the edge often toothed, clasping column; spur 5.5–7.5 cm long, pendent, swollen at apex.Anther erect, 5–8 mm high; canals 13–19 mm long, porrect, the tips upturned; stigmas porrect, 13–18 mm long, slender but enlarged and truncate at apex.Rostellum mid-lobe 3–5 mm long, triangular.