Japan Flora: robust and taller; culms 40-50 cm. long; leaf-blades flat,thin, 10-20 cm. long, 3-7 mm. wide; ligules 1-2 mm. long; panicles open, ovate, 10-20 cm. long, branches scabrous; spikelets vivid green, broadly ovate, 4-5 mm. long; glumes unequal, acute, scabrous on the keel, the upper narrowly ovate; lemmas 2.5-3 mm. long. May-July. Shaded waste places and parks.
Hokkaido, Honshu, Shikoku, Kyushu; common. Korea. Possibly a hybrid of P. acroleuca X P. annua.