Japan Flora: culms densely tufted, 40-70 cm. long, acutely angled, scabrous; leaf-blades 2-3 mm. wide, deep green, scabrous on the margin; spikes gynecandrous, obovoid to globose-ellipsoidal, 5-7 mm. long, the terminal one with a slightly longer staminate portion; pistillate scales acute, castaneous, lustrous; perigynia about as long as the scales, ovate, nearly 3 mm. long, plano-convex, veiny, pale green, becoming dark brown at maturity, slightly scabrous on the margins near tip, abruptly short-beaked and entire at tip. June-July. Sphagnum bogs.

Hokkaido, Honshu (Oze­gahara in Kotzuke Prov., and Mount Kirigamine in Shinano Prov.); rather common. Sakhalin and Kuriles.