Robust tufted perennial herb, 50–75 cm tall, glabrous, usually with 1–2 plants from a vertical woody rhizome. Rhizome 1–3 × 1–2.5 cm, hemispherical to shortly subcylindrical; roots numerous spreading long, fibrous to fleshy fusiform. Aerial stem absent. Leaves numerous, erect to arching, fleshy grass-like, broadly winged and sheathing at the base, successively enfolding the bases of inner leaves and peduncle; blade up to 50 cm long and 2–7 mm wide, narrowly linear-terete to narrowly strap-shaped and tapering to the apex, sometimes twisted throughout, expanded and winged in the lower 3.5–6.5 cm forming a dense stout base 1 × 2 cm in diameter sometimes persisting as a fibrous sheath; wings hyaline, up to 8 mm wide on each side of the blade. Peduncle usually 1, ascending-erect, terete, ± fleshy becoming stoutly rigid, 35–46(55) cm long and 3–6 mm in diameter. Raceme ± densely many-flowered, conical to cylindrical, 8–16 cm long increasing to c. 36 cm long in fruit; bracts 12–15 mm long, finely subulate and shortly hyaline-winged toward the base with hyaline auricles, persistent; pedicels ± closely spaced, slender, ascending-patent, mostly 5–13 mm long after anthesis, straight, becoming ± curved in the fruiting inflorescence, persistent. Tepals yellow with a green midrib, persistent, up to 9 × 4 mm, oblong, the outer 3 ± cucullate. Filaments c. 2–3 mm long, densely bearded in the upper part with long yellow hairs; anthers 1.5–2 mm long. Style c. 2.5 mm long, terete. Capsule inflated when mature, not stipitate, green becoming brownish, withered tepals persisting at the base, 8–10 mm long, 7–9 mm wide, subglobose, 3-lobed. Seeds 3–4 mm long (including wings), 3-sided, with the angles usually distinctly winged, the wings most obvious in young seeds, brownish-black.
