glabrous; rhizome 1/5 in. in diam., horizontal, woody; stems 2–6 in. long, thick, smooth, grooved, about 1/2 in. apart on the rhizome, each with 1 head; leaves all near the base of the stem, usually much overtopping the stem, 1/8– 1/5 in. broad at the base, deeply channelled, very tough, thick edges scabrous cutting, narrowed and triquetrous at the top; head 1/2– 3/4 in. in diam., compound, dense, pale brown; bracts 5–22, radiate, unequal, up to 1–3 in. long, resembling abbreviated leaves; spikelets 1/4– 1/3 in. long, 6–16-flowered, usually male at the top (some wholly male spikelets occur);glumes elliptic-lanceolate, acuminate, tip blunt, keel weak, otherwise nerveless; stamens 3; anthers linear-oblong, not crested; style as long as the glume, linear-cylindric, entire or microscopically notched at the tip; nut 1/3 the length of the glume, obovoid, round trigonous, very smooth, shining black; gynophore small, obconic. null
