Erect stems branching at midheight. Stems gray or green, ridged and covered with cobwebby hairs. Leaves 4–6 in., dotted with resin, deeply lobed into narrow, sharply pointed segments, widely spaced, entire at top. Flower head with a brown deep cup fringed at top, with pink or occasionally white disk flowers. Grows along roads, in light soils with some summer rain, below 6000 ft. Common invasive weed. Similar but shorter, diffuse knapweed, C. diffusa, has smaller, white to very pale pink flowers and fringed bracts with sharp points that turn outward.
- Rarity: Common
- Flowering Time: All Summer
- Life Cycle: Biennial, Perennial
- Height: 24--48 inches
- Habitat: East-Side Forest, West-Side Forest, Shrub-Steppe, Disturbed, Meadow
- Found In: East Gorge, Crater Lake Np, Mt. Rainier Np, Olympic Np
- Native: No