Digitalis thapsi many characteristics of "D. purpurea" after four to five generations of cultivation, and that the former became indistinguishable from the latter, a report that was considered "probably" trustworthy by Charles Darwin. "D. thapsi" and "D. purpurea" hybrids are generally fertile. "Digitalis thapsi" is widespread in Spain. A biennial evergreen plant, it flowers in late spring. A study of the fruiting activity in "D. thapsi" showed that production, size and number of seeds were interrelated. Analysis has shown that seed weight is not related to the length of the cotyledon, and that the length of the fifth leaf can serve as
Radioactive contamination from the Rocky Flats Plant of substantial contamination from the 1957 plutonium fire until after the highly visible 1969 fire, when civilian monitoring teams confronted government officials with measurements made outside the plant of radioactive contamination suspected to be from the 1969 fire, which consumed hundreds of pounds of plutonium (850 kg). The 1969 fire raised public awareness of potential hazards posed by the plant and led to years of increasing citizen protests and demands for plant closure. Releases from previous years had not been reported publicly prior to the fire; airborne-become-groundborne radioactive contamination extending well beyond the Rocky Flats plant was not publicly reported