Tufted. Stems ± erect, 10-30- (50) cm high. Leaves reduced to a single basal red-purple sheath. Inflorescence a cluster of numerous red-brown or red-purple spikelets, often proliferous. Stamen 1. Style-branches 2. Nut plano-convex or biconvex, cream to light grey-brown.

Culms 10–30–(50) cm. long, from slightly < 1 to 1.5 mm. diam., tufted, lfless except for a single, basal, red-purple sheath. Infl. an apparently lateral, solitary head of ∞ densely packed spikelets, often proliferous with 1–3 very slender branchlets each bearing a cluster of spikelets; bract subtending infl. variable in length, often > spikelets. Spikelets 3–5–(7) × 2–3 mm., oblong or elliptical, red-brown. Glumes c. 2 mm. long, ovate to obovate, subacute to obtuse, flattened at tip beside keel, light greenish brown with red markings to almost entirely dark red-purple, with ∞, often distinct, light brown nerves; keel rather narrow, us. prominent only in upper part of glume, occ. slightly excurrent; hyaline margins entire, us. well-marked. Hypog. bristles 0. Stamens us. 1, rarely 2–3 in lower fls of spikelet. Style-branches 2, very rarely 3. Nut c. 1 mm. long, slightly > 0.5 mm. diam., < glume, plano-convex or biconvex, obovoid, minutely apiculate with a dark tip, cream to light grey-brown, surface shining but minutely reticulate.