[USDA FEIS] Origins and Introduction: Bull thistle is native to Europe, from Britain and Iberia northward to Scandinavia, eastward to western Asia, and southward to northern Africa. It is found on every continent except Antarctica, although its distribution is confined mostly to the northern and southern temperate zones. Bull thistle is not native to North America. It is thought to have been introduced to eastern North America during colonial times, and to western North America in scattered locations in the late 1800s and early 1900s. Bull thistle is now common throughout the Pacific States, and it is the most common and widespread of pasture and rangeland thistles in western North America. (link added by Jessica Johnston)
Calflora:
Information on California plants for education, research and conservation,
with data contributed by
public and private institutions and individuals.
[web application]. 2025.The Calflora Database
[a non-profit organization].Available:
https://www.calflora.org/(Accessed: 03/28/2025).