Tufted. Stems rather rigid, 6-30- (50) cm high. Leaves 1- (3) or reduced to red-brown basal sheaths. Inflorescence a cluster of (1) -3-6- (10) spikelets, often proliferous. Glumes obtuse, flattened towards tip. Stamen 1. Style-branches 3. Nut distinctly trigonous, usually white.

Culms 6–30–(50) cm. × (0.4)–0.7–1.2–(1.8) mm., tufted, ∞, erect, often rather rigid, terete, bright green. Lvs 1, or rarely 2–3 at the base of the culm, < 1 mm. wide; frequently reduced to a single, mucronate, red basal bract, mucro us. short. Infl. an apparently lateral, solitary head of (1)–3–6–(10) crowded spikelets, often proliferous with 1–3 slender branchlets each terminated by a smaller head of spikelets, subtending bract us. slightly > spikelets. Spikelets (2)–3–4–(5) × 1.5–2.5–(3) mm., ovate or oblong-ovate, often dark red-purple. Glumes 1.5–2 mm. long, oblong-obovate, obtuse or ± acute, with a large dark red to black patch on either side of the pale green keel, with ∞ distinct, light brown nerves, margins entire, white and membr., flattened at the tip beside the keel. Hypog. bristles 0. Stamens 1, very rarely 2. Style-branches 3, or rarely 2–3. Nut c. 1 × 0.5 mm., slightly > ½ length of glume, conspicuously trigonous or occ. biconvex, distinctly mucronate, pale strawcoloured, almost white, occ. grey-brown, surface distinctly reticulate.