Perennial, 30-80 cm. Base of stem slightly swollen, with stolons to c. 20 cm, tuber up to 15 mm diam., round or elongate, rooting, covered by greyish-brown scales. Stem 2-3 mm diam., trigonous, smooth. Leaves shorter than stem; sheaths 50(-100) mm, yellowish or greyish brown, sometimes with reddish tint, mouth margin nearly straight or lingulate; blades to 30(-60) cm, to 5 mm wide, yellow-green, keeled, margin slightly revolute, smooth or towards apex scabrous, apex acute, trigonous, scabrous. Inflorescence an anthelodium, primary rays to more than 10, to 80 mm; lowest 2-3 bracts leaf-like, up to 30 cm, 5 mm wide, sheathless; primary branches end with often more than 20 spreading spikes in irregular spiral, but small secondary anthelodia frequent. Spikes up to 15 x c. 1.5 mm, elongating after flowering, with 5-12 flowers; glume-like bract c. 2 mm, glume-like prophyll two-veined, c. 1.5 mm, base swollen; rachis compressed, slightly zigzagging, internodes c. 1 mm, winged; glumes 2-2.5 mm, cymbiform, blunt, yellow-brown, with 5-9 conspicuous veins, mid-vein strong, with short mucro below glume apex, margins scarious. Nut c. 1.5 mm, ovoid or obovoid, obtusely trigonous, yellow-brown or dark-brown, surface reticulate-papillose.
Flowering: April-July.