Leafy tufts to ± 25 cm high. Inflorescence a cluster of 3-4 spikelets. Glumes often almost black with green keels. Stamen 1. Style-branches 2- (3). Nut usually biconvex, dull yellow-brown.

Tufts lfy from an ascending rhizome c. 1 mm. diam. Culms (6)–10–25–(40) cm. × c. 0.5 mm. Lvs 1–4, us. < culms, c. 0.5 mm. wide, linear, concavo-convex, sheath membr. with red-purple nerves, orifice truncate. Infl. apparently lateral, of (1)–3–4–(6) spikelets; subtending bract 1–3–(4) cm. long. Spikelets 2.5–4 × 1.5–2 mm., ovoid or elliptical. Glumes c. 1.5 mm. long, lanceolate, acute, dark red, almost black, or pale cream with red markings, keel green, strongly developed, excurrent. Hypog. bristles 0. Stamens 1–(3). Style-branches 2, or 3. Nut c. 1 mm. long, slightly > 0.5 mm., diam., biconvex, rarely trigonous, elliptical, distinctly mucronate, dull yellow to yellow-brown, with minutely reticulate but glossy surface.