Distribution
Marsh thistle is native to Europe and western Asia (Gleason and Cronquist 1991, Tutin et al. 1976). It is established in three northeastern states, and in Michigan and Wisconsin. It is also established in southeastern Canada and in British Columbia (not shown). Since the early 1930s, marsh thistle has spread from central Upper Michigan into northern Lower Michigan and northeastern Wisconsin. It is not yet known to occur in Minnesota.
For More Information
Wisconsin Background Maps (UW - Stevens Point)