Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east to the Atlantic Coast.
Habitat: In sluggish streams, ponds, lakes, and mudflats at low to moderate elevations.
Growth Duration: Perennial
Conservation Status: Not of concern
Pubescent, aquatic perennial, the stem flaccid, rooting at the nodes, 1-2 mm. thick and up to 1 m. long.
Leaves alternate, the submerged ones 3-7 times trichotomously or dichotomously dissected into filiform segments; floating leaves similar, or simple, 5-15 mm. long and twice as broad, 3-lobed and toothed.
Pedicels stout, 2-6 cm. long, recurved in fruit; sepals 5, membranous, 2-5 mm. long; petals 5, white, 5-10 mm. long; nectary scale very small, forming a minute pocket; receptacle globose, hairy; stamens 10-15; pistils 12-15.
Achenes 1.5-2 mm. long, thin-margined, compressed; stylar beak 0.6 mm. long, deciduous.