By Verna Gates Bristol Tenn. (Reuters) – A variety of sunflower found in some Southern states and two other rare plants were designated on Friday as endangered species by the U.S. federal government. The U.S. Fish and Wildlife Service listed the whorled sunflower, Short’s bladderpod and fleshy-fruit gladecress for protection under the Endangered Species Act because populations of the three are dwindling to critical levels. We do not have all of the knowledge to know what we can lose and what it is there for,” said Tom MacKenzie, spokesman for the Southeast Region of U.S. Fish and Wildlife. The whorled sunflower – sometimes called the giant sunflower – grows in open pastures and along roadsides, mostly in Alabama, Georgia and Tennessee.