Japan Flora: Rhizomes about 10 cm. long, 3-4 mm. in diameter, covered with coriaceous, white, ovate, slightly keeled, inflated scales about 5-10 mm. long; culms erect, 60-100 cm. long, simple or sparingly branched near the middle; leaf-blades 10-15 cm. long, 3-7 mm. wide; panicles 15-35 cm. long, the branches 2- to 4-nate, ascending; spikelets lanceolate, 3-3.5 mm. long; glumes 2/3-4/5 as long as the spikelets, very acute; lemma acuminate, the awn 3-4 mm. long, slightly curved at tip; anthers 0.8-1.2 mm. long. Aug.-Oct. Woods in moun­tains; Honshu (Japan Sea side of centr. distr.); rather rare.

var. nipponica Ohwi. Phase with erect awns 5-10 mm. long. Hokkaido, Honshu (Tajima Prov. and eastw.). s. Kuriles.