Identification

Common Name: Yellow Starthistle (Golden Starthistle, Yellow Cockspur, St. Barnaby's Thistle)
Scientific Name: Centaurea solstitialis

Thirty-two species of Centaurea are found in the United States. The common names of these plants include starthistle, knapweed, and cornflower.  Only two species, American starthistle (Centauria americana) and Alpine knapweed (Centauria transalpina) are native.