Clematis columbiana

Clematis columbiana (Nutt.) Torr. & Gray.
Engl.: Rocky Mountain clematis, climbing purple virgin's bower, rock clematis, whorl-leaved virgin's bower.
Bot. syn.: Atragene americana Sims., Atragene columbiana Nutt., Clematis pseudoalpina (Kuntze) A. Nels., Clematis verticillaris DC.