Japan Flora: Rhizomes sometimes elongate; culms slender, 20-50 cm. long, 1-1.5 mm. thick, terete, obsoletely striate, the sheaths 5-10 cm. long, somewhat reddish, transversely truncate at apex, some­times mucronate; spikelets ovoid to lanceolate, 7-20 mm. long, 3-5 mm. thick, acute, dark sanguineous and purplish brown; only the lowest scale empty and clasping, the others narrowly ovate, 4-5 mm. long, erect; achenes tawny, turgid-biconvex, 1-1.5 mm. long, nearly smooth, dull, the style base large, spongy, ovate to deltoid, 1-2 mm. long, nearly as broad as the achene, the bristles 5, slender, slightly shorter to as long as the achene, retrorsely scabrous, or in forma reducta (Ohwi) Ohwi. Kuro-hari-i, the bristles rudimentary or lacking. July-Oct. Wet places especially near the seacoast.

Hokkaido, Honshu, Kyushu; rare. Korea, Ussuri, Sakhalin, Ku­rils, Kamchatka, and northern N. America