Japan Flora: Culms stout, 1-2 m. long, with several nodes, obtusely 3-angled, smooth, sometimes with axillary tufts of leaves at nodes; leaves flat, with loosely incurved margin below, 8-10 mm. wide, very coarse and firm, coarsely serrulate-scabrons on margins, caudately acuminate in a long, subulate, somewhat 3-angled apex; partial inflorescences 5-7, corymbose, 4-8 cm. across, with very numerous, dense spikelets; spikelets oblong when mature, brown, 3 mm. long; scales broadly ovate, obtuse, about the 7 lower ones small and empty, the 3 upper large and nearly equal; achenes broadly ovoid, 2.5 mm. long, tawny, truncate, excavated at base. Aug.-Oct. Wet places near the seacoast.
Honshu (Awa and Noto Prov. and westw.), Shikoku, Kyushu. Ryukyus, Formosa, s. Korea, China, India, Malaysia, and Australia.