Centaurea solstitialis, yellow starthistle, golden starthistle, yellow cockspur, or St. Barnaby’s thistle, is a member of the Asteraceae that is native to the Mediterranean region. Since its introduction to North America in the mid-nineteenth century it has become a large-scale noxious weed there, currently dominating over 18 million acres (73,000 km²) in the United States alone.
