Aquatic with emersed, floating, or submersed leaves. Each leaf arises on long stem from base. Emersed leaves arrow-shaped, 2–15 in., nearly as long as broad, with lower lobes about as long as upper lobe. Bracts beneath inflorescence 1/5–1/2 in. long. Flowers up to 1 1/2 in. across and in whorls of 3 in a tall spike at top of leafless stem. White petals fall soon after opening. Female flowers in bottom whorl below male flowers with 25–40 stamens. Grows in freshwater ponds, ditches, marshes, at low elevations.
- Rarity: Locally Common
- Flowering Time: Late Summer
- Life Cycle: Perennial
- Height: 1--4 feet
- Habitat: Lake/Pond, Bog/Fen/Wetland
- Found In: Pacific Coast & Se Wn, West Gorge, Olympic Np
- Native: Yes