Yellow Starthistle
Centaurea solstitialis
Description
A winter annual that has an erect and rigid stem, has many branches and is covered with cottony hair. It bears yellow flowers and long, sharp spines on the flower heads. Basal leaves are deeply lobed and stem leaves are narrowly oblong.Habitat
It grows wherever cheatgrass grows, as well as in canyon grasslands, rangelands, pastures, edges of cropland, open woodlands, roadsides and disturbed areas.Distribution
Northeastern and southwestern Oregon, most of Washington, most of Idaho (especially western)Impacts
Depletes soil moisture in grasslands, reduces land value of recreational areas, and displaces native plants, decreasing wildlife forage and, thus, native plant and animal diversity. In the Agate Desert Preserve in southwest Oregon, it is threatening Lomatium cookie, a globally rare plant species.Dispersal Methods
Wind, human activities (such as vehicles, road maintenance, and contaminated crop seed or hay), birds, livestock, water, and soil movementPrevention
Look for yellow starthistle in canyon grasslands, rangelands, pastures, edges of cropland, open woodlands, roadsides and disturbed areasListings
ODA's B ListFactsheets
Photos
Distribution Map
Distribution in Washington
Distribution in Idaho
Other Links
Article from the University of Idaho on Methods of Combating Yellow Starthistle
Overview of the Basic Biology, Distribution, and Vegetative Suppression of Four Knapweed Species in Washington