Rhizome short. Stems rush-like, densely crowded, rigid, terete, often ± compressed, to 90 cm high. Leaves reduced to red-brown basal sheaths. Inflorescence a single hemispherical head, of numerous small densely crowded red-brown spikelets with a short terete pungent bract.

Rhizome short, 5–10 mm. diam., woody, covered with red-brown bracts 5–10 mm. long. Culms (15)–30–90–(120) cm.×1–2 mm., densely crowded on the rhizome, rush-like, rigid, erect, terete or slightly compressed, striated when dry. Lvs reduced to 3–6 basal sheaths, the uppermost 5–13 cm. long, brown or red-brown, the oblique orifice slightly dilated. Infl. an apparently lateral, solitary, hemispherical head, 0.7–1.5 cm. wide, of ∞, densely crowded, sessile spikelets; subtending bract continuous with the culm, rigid, erect, pungent, > infl. Spikelets 3–4 mm. long, ovoid, light brown. Glumes broadly ovate, obtuse, margins entire, ± apiculate, reddish towards the tip, lateral nerves conspicuous. Hypog. bristles 0. Stamens 3. Style-branches 3. Nut c. 1 mm. long, < 1 mm. wide, plano-convex to trigonous, apiculate, dark brown to black, shining.