Tufted annual or perennial. Culms trigonous, smooth, 5–80 cm high, to 2 mm diam. Leaves not septate-nodulose, equalling or shorter than culms, 1–3 mm wide. Inflorescence simple with 3–5 branches to 5 cm long, or head-like; clusters subdigitate or spicate, hemispherical, to 2.5 cm diam.; involucral bracts leaf-like, 1–3 exceeding inflorescence. Spikelets flattened, 2–25 per cluster, 5–20 mm long, 2–3 mm wide in side view, 6–36-flowered; rachilla not winged, persistent; glumes obtuse, with keel 1–3-nerved, dark red-brown to blackish, margins pale, often with a hyaline patch on sides, 1.5–2.5 mm long, 1.5–2 mm wide in side view; stamens 2 or 3. Nut biconvex, broad-obovate to orbicular, brown to blackish, from one-third to one-half as long as glume, 0.8–1.5 mm long, 0.6–1.2 mm wide. Flowers spring–summer.
LoM, MuM, Wim, VVP, VRiv, GipP, Gold, CVU, GGr, NIS, EGL, EGU, HSF, HNF, Strz, MonT, VAlp. All mainland States except NT. Malesia, Asia, Africa. Scattered, mostly in the southern part of the State, chiefly on sandy or alluvial soils around swamps and on stream-banks, occasionally appearing in disturbed sites. .
