Glabrous. Rhizome horizontal, stout. Stems 1 1/2–2 1/2 ft. long, at the top triquetrous and smooth or nearly so. Leaves 3/4 the length of the stem, 1/6– 1/4 in. broad. Umbel simple; rays 8–10, up to 1–1 1/2 in. long; bracts 4–6, similar to the leaves, lowest up to 7 in. long. Spikes 1 1/4 by 1/2 in., exactly cylindric, with 20–40 distinct spikelets. spreading at right angles, bright-red in flower, red-brown in fruit. Spikelets 1/4– 1/3 in. long, oblong or lanceolate, hardly compressed, often 4-flowered, maturing 3–2 nuts, disarticulating in one piece above the two lowest empty glumes. Nut-bearing glumes ovate, obtuse, strongly 9–13-ribbed, hardly keeled, hardly remote but (even before the nut is ripe) obliquely and rigidly spreading. Nut 2/3 the length of the glume, broadly oblong, trigonous, black-brown. Style 1/2 the length of the nut; branches 3, long, much exserted.