Japan Flora: Rhizomes elongate, slender; culms 20-50 cm. long, glabrous; leaf-blades soft, flat, bright green, 2-5 mm. wide, the sheaths parrially dark reddish purple; spikes 2-4, distant, the terminal staminate, broadly linear, 1.5-2 cm. long, dark purplish brown, the lateral pistillate, short-cylindric, rather densely many-flowered, long-peduncled, 1.5-2 cm. long, the bracts short-bladed, long-sheathing; pktillate scales ovate, dark purplish brown or dark reddish purple; perigynia longer than the scales, ascending to spreading, obtusely 3-angled, ovoid, membranous, glabrous, faintly nerved, abruptly short to rather long-beaked, with an obsoletely 2-toothed apex; stigmas 3. June-July. Woods in mountains.

Hokkaido, Honshu (Mount Yakeishidake in Rikuchu Prov.); rare. e. Siberia, Sakhalin, Kamchatka, s. and centr. Kuriles, and Korea. The typical phase occurs in Canada, Siberia, and Eu­rope.