Wavyleaf Thistle (Cirsium undulatum (Nutt.) Spreng.)

↑Range - Expand

Legend	Color
Native
Extirpated
Expanded
Native or Not Present
Native or Expanded
Expanded or Not Present
Native or Expanded or Not Present

This tentative map is based on our own research. It may have limited data on Canada and/or Mexico, and there is some subjectivity in our assignment of plants as introduced vs. expanded. Read more in this blog post.

Although this plant occurs somewhere in each of these regions, it may only occur in a small part of some or all of them.

This is a weedy plant with wind-dispersed seeds; it has expanded its range both southwest into California, where it is considered invasive, and eastward, mostly in the midwest but slightly beyond. At the same time, some of its populations near the edge of its range, such as in Missouri, have been locally extirpated. We marked the new range expanded even though it is scattered and rare in much of the new region, because there is a clear pattern of establishment on new sites. In the east, it remains uncommon and not invasive.