Japan Flora: Slender herbs; culms 10-60 cm. long, smooth; leaves filiform, involute, 0.5-1.5 mm. wide; corymbs 1-3, loosely arranged, small; spikelets lanceolate, whitish, 4-6 mm. long; achenes obovate, 2-2.5 mm. long, with faint transverse wrinkles, the beak half as long as the achene, compressed, glabrous; bristles 9-15, longer than the achene, retrorsely scabrous, with minute ascending ciliae near base. July-Oct. Wet places and bogs.
Hokkaido, Honshu, Kyushu (rare). Europe, Asia, and c. N. America.