Centaurea biebersteinii
Asteraceae
Spotted Knapweed
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: Early Summer, Mid Summer, Late Summer
- Flower Form: Smooth leaves, Thistle
- Life Cycle: Biennial, Perennial
- Height: 24–48 inches
- Habitat: Disturbed, East-side Forest, Meadow, Shrub-Steppe, West-side Forest
- Found In: Crater Lake NP, East Gorge, Mt. Rainier NP, Olympic NP
- Native: No
- Latin Synonyms: Centaurea stoebe ssp. micranthos, Centaurea stoebe
