Plants (20–) 50–110 (–170) cm tall, usually robust, forming large and often dense stands; rhizome 2.5–10 mm in diam., with 1–4 cm long internodes. Cataphylls usually 3, large, (10–) 15–25 cm long, with awnlike blade; upper cataphylls distally stramineous, stramineous-brown in the middle, darker towards the base, ±dull, adaxial side silvery stramineous; lower cataphyll often blackish brown, glossy. Stem (1–) 3–10 mm thick, terete, not compressed or twisted; pith of astericiform cells, often interrupted. Lower bract usually 7–15 (–40) cm long. Inflorescence much branched, 2–15 cm, dense, with 20–several hundred flowers, usually partly congested (sometimes wholly), partly of ±dense heads on peduncles to 6 cm long and c. 0.5–0.7 mm in diam. Bracteoles ovate, 1.5–2.0 mm long, acute, reddish brown. Tepals subequal, 4.5–6 mm long, narrowly lanceolate; outer tepals acute-acuminate; inner tepals ±acute; central band pale brown to dark castaneous-brown; otherwise red-brown to dark castaneous-brown; margins narrow. Anthers 1.3–1.7 mm long; filaments 0.6–0.8 mm long; style 0.7–1.0 mm long; stigmas c. 1.0–2.0 mm long. Capsule ellipsoid-ovoid, trigonous, c. 3.8–5.5 mm long, shorter than or equalling perianth, acuminate, gradually narrowing into c. 0.5 mm rostrum. Seeds ellipsoid, pale brown, c. 0.6–0.8 × 0.3–0.4 mm, faintly reticulate; appendages absent.