Meadow Knapweed
Centaurea pratensis (C. jacea x C. nigra)
Description
A perennial with one to several upright-branched stems growing from a woody root. Because it is a hybrid species, traits are variable. The leaves are usually coarsely lobed and long, larger at the base of the plant and smaller on the upper stem. The flower head has a large, light to dark brown bract with a torn, thin papery margin or comb-like, fringed margin. It bears bright pink flowers that bloom from July to September.Habitat
Moist sites, including irrigated pastures, forest openings, moist meadows, rivers and streams, and roadsidesDistribution
Primarily west of the Cascades, some sparse populations in eastern Washington, Oregon, and northern IdahoImpacts
Out-competes native or desirable species, reduces forage for wildlife and livestockDispersal Methods
Water, vehicles, contaminated gravel or hay, and wildlifePrevention
Survey for pre-flowering or flowering May through July along moist roadsides, sand or gravel bars, river banks, irrigated pastures, moist meadows, and forest openings. It also can invade industrial sites, tree farms, and grasslands. Small, isolated populations can be dug up, but should be monitored for regrowth for several years. Wash vehicles, shoes, and animals that have been in infested areas to prevent spread.Listings
ODA's B ListFactsheets
Washington State Noxious Weed Control Board Fact Sheet
Photos
Distribution Map
Distribution in Washington
Distribution in Idaho
Identification Help
Other Links
Best Management Practices of Knapweed Species
The Seattle Times: In war on weeds, the Bug Lady bets on hungry weevils