Japan Flora: Coarse annual; culms 80-120 mm. long, rather thick, branching at base; leaf-blades linear, flat, 30-50 cm. long, 1-2 cm. wide, scabrous, scarcely thickened on margin; ligules wanting; sheaths smooth, often reddish in lower ones; panicles exserted, more or less nodding, 10-25 cm. long, rather densely branched, the branches (ra­cemes) to 3-5 cm. long, ascending, sessile; spikelets 3-4 mm. long, densely arranged on branches, ovoid, often long-awncd, pale green and often dull purplish, short bristly on nerves; first glume about 2/5 as long as the spikelet, deltoid, the sec­ond as long as the spikelet, short-awned; sterile lemma mem­branous, with a straight scabrous awn 2-4 cm. long, or awn­less; fertile lemma ovate-elliptic, acute, pale yellow, lustrous, smooth, 3-3.5 mm. long. Aug.-Oct. Wet paddy fields and ponds.

Honshu, Shikoku, Kyushu; very common and variable. Widespread in all warmer regions.

f. kanashiroi Ohwi. Leaf-blades and sheaths pilose. 

var. praticola Ohwi. An awn­ less, more slender plant. July. Very common in (not wet) lowlands; Hokkaido, Honshu, Shikoku, Kyushu. Formosa, Ryukyus, to Korea.

var. formosensis Ohwi. Intermediate between the typical phase and the following variety; leaf-blades narrower; spikelets pale green; first glume about 2/5 as long as the spikelet; sterile lemma thickened, lustrous, glabrous, at least on the back. Honshu, Shikoku. Formosa, China, and India.

var. oryzicola (Vasing.) Ohwi. Culms nearly erect from base; leaf-blades thickened on mar­gins, scabrous; panicles usually pale green, erect, spikelets about 5 mm. long, awnless or short-awned; first glume 1/2-3/5 as long as the spikelet; sterile lemma often thickened and coriaceous, glabrous, lustrous. Aug.-Oct. Wet places; common in paddy fields; Honshu, Shikoku, Kyushu; a troublesome weed. China, Korea, and India.