Japan Flora: Perennial; culms tufted, branched at base, about 1 m. long, rather thick; leaf­blades 30-60 cm. long, 2-4 cm. wide; involucral bracts ovate, hard, lustrous, about 1 cm. long; first glume of staminate spikelets herbaceous, oblong, obtuse, pale green. Frequently cultivated and sometimes naturalized in our area. 

var. mayuen (Romain) Stapf. Similar to the typical phase but annual, the inflorescence often drooping and with broader bracteal leaves; involucral bracts crustaceous, elliptical or oblong. Fre­quently cultivated in our area, possibly native of Indochina or China.