Japan Flora: Stems simple or slightly branched; floating leaves spathulate or oblanceolate, sometimes not developed, obtuse, gradually narrowed to the base, many­nerved, the lower submersed leaves sessile, the upper short- petiolate, narrowly lanceolate, narrowed toward the base, 7-nerved, obtuse to acute; peduncles 5-20 cm. long; spikes 2.5- 4 cm. long; nutlets obovate, with 3 dorsal ridges; style short.

Reported from Hokkaido. Cooler regions of the N. Hemisphere.