Japan Flora: Rhizomes short-creeping, in loose tufts; culms smooth, obtusely angled, 15-40 cm. long; leaf­blades flat, stiff to rather soft, 5-10 mm. wide, scabrous or slightly so, 2-ribbed on upper surface, the basal sheaths dark brown to dark reddish brown, dull; spikes 3-5, loosely arra­nged, on erect exserted peduncles, the terminal staminate, linear, 1.5-3 cm. long, the others pistillate, short-cylindric, 2-3 cm. long, densely many-flowered, the bracts very short-bladed, with prolonged inflated sheaths; pistillate scales ovate, abruptly cuspidate, reddish brown to pale green; perigynia spreading, broadly obovoid, light yellow-green, 2.5-35 mm. long, glabrous, nerved, with a rather long recurved beak, acutely 2-toothed at tip; stigmas 3. Woods in mountains.

Hokkaido, Honshu, Kyushu; common. Sakhalin.

var. latissima (Ohwi) Akiyama Leaves 15-20 mm. wide. Especially abundant in mountains on the Japan Sea side of Honshu.