Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to California, east to the Atlantic Coast.

Habitat: Lakes and ponds, tolerant of deep waters.

Flowers: June-August

Origin: Native

Growth Duration: Perennial

Conservation Status: Not of concern

Pollination: Wind

Aquatic, herbaceous perennials from slender rhizomes, the terete stems up to 4 mm. thick and 1 m. long, simple or sparingly branched above.

Leaves alternate, the submersed leaves short-petiolate, the upper ones 8-20 cm. long and 2-5 cm. broad, acute at both ends, folded, and sickle-shaped in outline, 25- to 45-nerved; floating leaves with long, stout petioles, the blades leathery, ovate to ovate-elliptic, acute or rounded at the base, 5-10 cm long and 2-4 cm. broad; stipules to 10 cm. long, free of the petiole.

Flowers perfect, in densely-flowered spikes on peduncles 7-15 cm. long; perianth of 4 clawed segments, each with an upturned, oval blade; stamens 4, fused with the claws; pistils 4, sessile.

Achenes obliquely ovoid, 4-5 mm. long, with a sharp dorsal keel and 2 lateral keels.