Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east to the Rocky Mountains, Great Plains, Great Lakes region, and eastern North America.

Habitat: Deep water of lakes.

Flowers: May-July

Origin: Native

Growth Duration: Perennial

Conservation Status: Not of concern

Pollination: Wind

Aquatic, herbaceous perennials from slender rhizomes, the stems up to 3 m. long, sparingly branched, slightly flattened, 2-3 mm. thick, whitish, the shorter internodes zigzag.

Leaves all submersed, the blades sessile, with a clasping base, oblong-lanceolate, 1-2.5 dm. long and 2-3 cm. broad, entire, the tip rounded and somewhat hooded; stipules free of the blade, 4-10 cm. long, whitish.

Flowers perfect, in dense spikes 2.5-5 cm. long; peduncles club-shaped, 1-3 dm. long; perianth of 4 clawed segments, each with an upturned, oval blade; stamens 4, fused with the claws; pistils 4, sessile.

Achenes obovoid, 4-5 mm. long, with a short beak and prominent dorsal keel.