Japan Flora: Rhizomes short-creeping, thick; culms stout, 40-60 cm. long; leaves flat, 2-4 mm. long, abruptly acute, rather firm; inflorescence com­pound, with rather many spikelets, 4-6 cm. long, the bracts 2-5, much exceeding the inflorescence, to 30 cm. long; spikelets rather densely arranged, narrowly ovoid to narrowly oblong, 7-15 mm. long, 3-4 mm. thick, acute, terete, lustrous, yellow­ish brown; scales rather firm, 3.5 mm. long, broadly ovate, obtuse, not keeled; achenes obovate-orbicular, biconvex, tawny, lustrous, with distinct, elevated, rectangular reticulations; stamens 3, the anthers nearly 1 mm. long.  Aug.-Oct. Marine, wet places.

Honshu, Shikoku, Kyushu. Korea, Northeast, and China.