Japan Flora: Leaves 5-10 mm. wide, gradually narrowed to tip; staminate portion of spikes 10-30 cm. long, the pistillate 6-20 cm. long, the naked axis between them 2-6 cm. long. June-July. Shallow ponds and riversides in lowlands.
Hokkaido, Honshu, Kyushu. Warmer parts of Eurasia and the Mediterranean region.