Erect, from rhizomes forming dense colonies. Stems ridged, branched, leafy, with pungent odor. Leaves 1–2 in. wide, dotted with glands but hairless. Leaves pinnately divided into pairs of leaflets that divide into sharply-toothed lobes. Flower heads 20–200, held in dense flat-topped clusters, small disk flower buttons, no ray flowers. Grows in fields, along roads and other urban areas, at low elevations. Can cause skin irritation.
- Rarity: Locally Common
- Flowering Time: Late Summer-Autumn
- Life Cycle: Perennial
- Height: 24--40 inches
- Habitat: Coastal, Meadow, Disturbed
- Found In: Columbia Basin, Olympic Np, Mt. Rainier Np, N Cascades Np
- Native: No