Distribution: Occurring chiefly west of the Cascades in Washington; Alaska to California, east to much of Canada and eastern United States.
Habitat: Shallow ponds and sluggish streams.
Conservation Status: Not of concern
Herbaceous, aquatic perennials from slender rhizomes, with elongate, branching stems covered with a gelatinous sheath.
Leaves mostly near the stem tips, floating, the petioles 5-40 cm. long, the blades broadly elliptic, the petiole attached near the center, 5-10 cm. long
Peduncles 5-20 cm. long, 1-flowered; sepals and petal 3 each, similar, purplish, narrowly oblong, 10-15 mm. long; stamens 12-30, purplish, about equal to the petals; pistils 9-15, 1-celled, superior.
Fruit leathery, narrowly ovoid, 6-8 mm. long, 1-2 seeded.