Distribution: Widely distributed on both sides of the Cascades crest in Washington; Alaska to California, east to Northwest Territory, Alberta, and the Rocky Mountain States.
Habitat: Ponds, shallow lakes, oxbows, and sluggish streams from low to middle elevations.
Growth Duration: Perennial
Conservation Status: Not of concern
Aquatic, perennial herbs with thick rhizomes bearing directly the flowers and leaves.
Leaves mostly floating, the terete petiole up to 2 m. long, the cordate blade 1-4 dm. long and about 2/3 as wide, leathery.
Flowers solitary, showy, long-pedunculate, perfect; sepals usually 9, the outer ones leathery, greenish, and shorter than the bright yellow inner ones, which are 3.5-6 cm. long, obovate and truncate; petals 10-20, thick, lanceolate, greenish-yellow, much smaller that the sepals, nearly equaling the numerous reddish or purplish stamens; style 1; stigma 13- to 25-rayed, 2-2.5 cm. broad.
Capsule ovoid, 5-9 cm. long, prominently ribbed