Rhizomatous perennial. Rhizome relatively short, stout, tough. Culms (15–)30–90(–120) cm high, terete or slightly compressed, 1–2 mm diam., numerous, closely packed, usually rigid and erect. Leaves reduced to basal orange-brown sheaths, 3–6 per culm. Inflorescence a dense globose or hemispherical head 7–20 mm diam., with numerous spikelets; involucral bract rigid, pungent, exceeding inflorescence; spikelets 3–4 mm long; glumes ca. 6–8, obtuse, sides irregularly several-nerved, red-brown, 2–2.5 mm long; stamens 3; anthers c. 1 mm long; style 3-fid. Nut plano-convex to unequally trigonous, irregularly ellipsoid, smooth, glossy, dark brown to black, about half as long as glume, c. 1–1.25 mm long, c. 0.7 mm diam., with small basal hyaline or white lobed disk deciduous or persistent. Flowers spring.
LoM, MuM, Wim, GleP, Brid, VVP, GipP, OtP, WaP, Gold, CVU, GGr, DunT, EGL, EGU, WPro, HSF, OtR, Strz. Also WA, SA, Qld, NSW, LHI, NI,Tas. Circumpolar in the southern hemisphere. Widespread on near-coastal sandy soils, with inland occurrences in sandy mallee tracts, the Grampians, heathlands of the south-west and margins of saline and subsaline lakes and watercourses on and near the basalt plain.
