Caespitose perennial, 25-40 cm. Rhizome short, producing tillers. Stem 1-1.5 mm diam., terete, deeply grooved, greyish green. Leaves c. half of stem length, basal; sheaths 20-100 mm, apparently all with blades, outer dark to blackish brown, stiff, glossy, inner from pale brown to greenish, one side scarious, brown or yellowish, mouth margin deeply oblique; ligule 0.3-0.5 mm; blades 0.5-1 mm diam., thick, crescentiform in transverse section with narrow adaxial surface, or channelled, greyish green, margins smooth or slightly scabrous, apex channelled, obtuse, scabrous. Inflorescence 8-15 x 5-10 mm, ellipsoid, later obconical or almost globose, composed mostly of 5-10, tightly overlapping spikes; lowest bract or, occasionally, two lowest foliose, up to 45 mm; spikes 7-9 x 1.5-2.5 mm, fusiform, compressed, 1-3 in axil of each bract, sessile or peduncle c. 1.5 mm; glumes distichous, keeled, acute, with strong, scabrous mid-nerve, brown to blackish brown, lowest two sterile, c. 4-5.5 mm, following 2-3 fertile, c. 6 mm, and uppermost 2-3 smaller, sterile. Perianth bristles 0-5, when present much shorter than the nut and not falling with it; stamens 2-3, anthers 3-4 mm. Nut 1.4-1.6 x 1-1.1 mm, widely ellipsoid or almost globose, obtusely trigonous, smooth, white, glossy.

Fl. Per.: April - June (-August).

Type: ”In Europae paludibus aestate, exsiccatis”. Herb. Linn. 68.5, 68.6 (LINN), the protologue names Gotland and the latter is from there.

Damp slopes, by springs, small streams and rivers; to c. 2000 m; Distribution: C. and S. Europe from Atlantic coast to the Crimea, Caucasus, N. and S. Africa, Yemen, Israel, Lebanon, Syria, Turkey, east to Pakistan, Uzbekistan, Tadjikistan; introduced to N. and S. America.