Perennials, usually 50–120 cm tall, densely caespitose; rhizome very short-noded, stout. Stem leafless, terete, 1.2–3 mm diam. (locally to 8–10 mm at base), bluish green, glaucous, soft; ridges 10–22, conspicuous, flat, widely separated from one another; subepidermal sclerenchyma strands present and coordinated with, but scarcely connected to the largest vascular bundles; epidermis cells enlarged on the ridges; bundles in three distinct rows; pith interrupted, subdense sometimes reduced to septa-like plates, of astericiform cells. Cataphylls 3–5; upper cataphylls mostly 5–15 cm long, usually loose, sometimes tight, blunt or with small, awn-like blade glossy, distally rarely stramineous-brown, adaxially pale stramineous above, deep golden brown at base. Lower bract usually 12–20 cm long, several times as long as inflorescence, with narrow sheath. Inflorescence pseudolateral; flowers mostly 50–120 but occasionally fewer or up to 200, solitary. Tepals (2.5–) 3–4 mm long with outer ones usually longer, lanceolate, acuminate to apiculate, variously coloured, often castaneous with broad green central band, becoming stramineous in ripe fruit; margins narrow, membranous. Stamens 6 (very rarely 3–5); anthers 0.7–0.9 (–1.2) mm long, 1–1.5× as long as c. 0.5–0.7 mm filaments; style c. 0.5 mm long; stigmas 0.8–1.5 mm long. Capsule trilocular, trigonous-ovoid to trigonous-ellipsoid, 2.5–4 mm long, slightly shorter than or considerably exceeding perianth, acute, mucronate, usually pale brown to castaneous, often glossy. Seeds obliquely ovoid, c. 0.4–0.6 × 0.2–0.3 mm, reticulate; appendages absent.