Cirsium pulcherrimum, called Wyoming thistle , is a North American species of plants in the thistle tribe within the sunflower family. The species is native to the western United States, primarily in the State of Wyoming but also in surrounding areas (Montana, Colorado, eastern Idaho, western Nebraska, northeastern Utah, and the Black Hills of South Dakota). Varieties \n* Cirsium pulcherrimum var. aridum (Dorn) D.J.Keil - Carbon, Fremont, + Sweetwater Counties in Wyoming \n* Cirsium pulcherrimum var. pulcherrimum - most of species range