Annual, 10-30 cm, forming small tufts. Stem 1-1.5 mm diam., trigonous, smooth. Leaves basal, shorter than stem; sheaths 20-40 mm, brown or reddish brown, mouth margin concave; ligule c. 0.7 mm, scarious, brown, arch of attachment as high as wide or higher; blades 2-3 mm wide, flat or keeled, margins smooth, apex long, trigonous, acute, scabrous. Inflorescence an irregular, spreading multiple spike, primary branches often up to 30 mm, with tubular prophyll, ending into cluster of to c. 50 spikes; lowest 2-3 bracts foliose, 3-10 (20) cm, sheath-less, margins and midnerve below scabrous, base with scarious margins. Spikes 3-15 x 1.5-2 mm, compressed, tight, with 10-40 glumes; rachis laterally compressed or quadrangular, brown or, usually, dark reddish brown, shiny, almost straight, internodes c. 0.5 mm; glumes 1-1.3 mm, cymbiform, mucronate, sides wide, scarious, usually dark reddish brown, basal margins protruding, scarious. Stamens 2; stigmas 3, sometimes 2. Nut c. 0.8 mm, ellipsoid, trigonous or convex, lateral angles sharp, yellow-brown, very finely reticulate.

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

Type: "Habitat in Galliae, Germanieae, Helvetiae pratis humidis.".

By rivers, stream and canal margins, flooded areas, moist fields; 5000-8000 ft; Distribution: From C and S Europe and N Africa to China, N Vietnam and Laos; Iraq, Turkey, Caucasus, Turkmenistan, Uzbekistan, Tadjikistan, Pakistan, India.