Japan Flora: Culms 1-1.5 m. long, stout, obtusely 3-angled, with 5-8 distant nodes; cauline leaves flat, 30-40 cm. long, 5-15 mm. wide, acute, rather sti汪，gradually narrowed at tip; partial panicles compound, 1-4, the lateral ones small, the terminal often de­compound, the bracts 2 or 3, longer or shorter than the partial inflorescence; spikelets peduncled or sessile, sometimes in clusters of 2-5 (forma concolor Ohwi. Abura-caya), some­times solitary (forma wichurae. Aiba-so), oblong or ellip­soid, 4-8 mm. long, 3-4 mm. thick, obtuse, reddish brown; scales narrow-ovate, 2-2.5 mm. long; achenes compressed- trigonous, 0.8-1 mm. long, obovate, pale, mucronate, the bristles 6, about 4 mm. long, slender, flexuous, ascending, scabrous at tip. Aug.-Oct. Wet places in hills and low­ lands.

Hokkaido, Honshu, Shikoku, Kyushu; common and variable. 

var. asiaticus (Beetle) T. Koyama. Lateral partial panicles usually wanting, the terminal one large, with numerous spikelets; spikelets dense, globular; scales ovate to broadly so. Honshu, Shi­koku, Kyushu. Korea, China to the Himalayas.