Gaillardia aestivalis By Matt Young March 10, 2014 12:00 MST Photograph by Lynn Wilhelm. Photography contest, Honorable Mention. Gaillardia aestivalis var. winkleri ‘Grape Sensation’ – Winkler’s White Firewheel-Purple selection, JC Raulston Arboretum Raleigh, North Carolina. Ms. Wilhelm adds, “This cultivar (cultivated variety) is a selection by the Stephen F. Austin State University Mast Arboretum in Nacogdoches, Texas, in honor of the school color. The natural variety is white with a yellow center and is found only in one county in Texas. Gaillardia aestivalis depends on fire to reduce competition in its native habitat (hence the common name).”