Very funy shape, attractive to wildlife:
I think it's actually Liatris squarrosa. The open "button" flowers (as opposed to the more often seen purple spikes) are one of its characteristics
Another characteristic is the scaly flower bracts, shown clearly in the first photo. It all the scales were out and then downward-pointing (like a collie's ears), then it might be L. ligulistylis.
It's relatively small for a liatris, and somewhat later blooming than most. For example, in my garden in southern Wisconsin, L. spicata is just finished, L. ligulistylis is starting, L. cylindracea is in mid-bloom, and L. punctata and L. squarrosa haven't begun blooming yet.