Japan Flora: Culms stout, more than 1 m. long, gla­brous, leafy; cauline leaves flat, linear, 20-30 cm. long, 8-10 mm. wide, the sheaths 4-5 cm. long; inflorescence terminal, compound, 5-10 cm. long, the lower 2 or 3 bracts longer than the others, leaflike, narrow, exceeding the inflorescence, the rays smooth, sometimes with short branchlets; spikelets sessile, disposed in capitate clusters of 8-10 spikelets, broadly ovoid, obtuse, 2-2.5 mm. long, dark gray; scales about 1 mm. long, very obtuse; achenes slightly shorter than the scale, ellipsoid, pale, compressed-trigonous; bristles 4-5, slender, erect, with a few spines at tip; anthers 0.8 mm. long. 

Honshu (Iwaki); rare. N. America.