Penstemon digitalis the plant's cultivars is named Husker Red because of its red foliage that has white or bluish-pink flowers. The Perennial Plant Association chose the Husker Red cultivar of "Penstemon digitalis" as the 1996 Perennial Plant of the Year. The author of the book "Perennial All-Stars" described Husker Red as "a stunning flowering perennial" and that "you can easily see why the Perennial Plant Association chose this perennial above all others". Husker Red was named after the Nebraska Cornhuskers. The other cultivar, Mystica, is green at first and then later changes to red in the fall. There is a hybrid of
Radioactive contamination from the Rocky Flats Plant tests." As noted by Carl Johnson in Ambio, "Exposures of a large population in the Denver area to plutonium and other radionuclides in the exhaust plumes from the plant date back to 1953." Weapons production at the plant was halted after a combined FBI and EPA raid in 1989 and years of protests. The plant has since been shut down, with its buildings demolished and completely removed from the site. The Rocky Flats Plant was declared a Superfund site in 1989 and began its transformation to a cleanup site in February 1992. Removal of the plant and surface contamination was