Stems single to few arising from a thickened base with open chambers. Sap turns reddish brown when exposed to air. Leaves 3 times pinnately divided into narrow lance-shaped to oblong leaflets 1/3–4 in. long, coarsely saw-toothed. Secondary veins end at gap between teeth. White to greenish flowers in 15–30 small crowded clusters form a mostly bractless umbel. Widespread in wet places, shallow water, below 3000 ft. Very toxic plant, should be carefully avoided. If you get juice of plant on your hands, wash immediately. Even small amounts can cause death if eaten.
- Rarity: Common
- Flowering Time: Early Summer
- Life Cycle: Perennial
- Height: 2--6 feet
- Habitat: Coastal, Vernal Wet, Meadow, West-Side Forest, East-Side Forest, Bog/Fen/Wetland
- Found In: Columbia Basin, West Gorge, East Gorge, Siskiyous, Great Basin, Steens, Mt. Rainier Np, Olympic Np, N Cascades Np
- Native: Yes