Liatris compacta

Liatris compacta, sometimes called Arkansas gayfeather, is a herbaceous plant species in the family Asteraceae and genus Liatris. It is native to the Ouachitas of west-central Arkansas and eastern Oklahoma in the central United States, where it is found growing in habitats such as rocky ridges, bluffs, hillsides, weathered sandstone, and open woods. It blooms in June to September and may start blooming as early as May, it has purple flowers grouped into heads. It was known as a variety of Liatris squarrosa as Liatris squarrosa var. compacta until relatively recently. ...read more on Wikipedia.