RENO, Nev. (AP) — Few people had ever heard of Tiehm’s buckwheat when conservationists filed a petition two years ago to declare the desert wildflower an endangered species. But federal documents show the rare plant at the center of a fight over a proposed lithium mine in Nevada has been on the government’s radar for decades. Conservationists who discovered the records are urging the Bureau of Land Management to create a protective buffer around the flower 200 miles northwest of Las Vegas. The request for administrative action comes while the Fish and Wildlife Service considers formal listing of the plant under the Endangered Species Act.