[Wikipedia] Endangered species status: Oenothera californica ssp. eurekensis, the rare Eureka Dunes evening primrose, is a federally listed endangered species endemic to only a few occurrences in the Eureka Valley Sand Dunes in the Eureka Valley of Inyo County, eastern California.[5] It grows alongside another local dune endemic, the endangered Eureka Valley dune grass (Swallenia alexandrae).[6] It is sometimes listed as its synonym Oenothera avita ssp. eurekensis. The Eureka Valley Sand Dunes are within Death Valley National Park. The main threat to the Eureka Dunes evening primrose was off-road vehicle use. That threat has been reduced and the plant's population has improved, but is still threatened by other human activities and an invasive species of tumbleweed, Prickly Russian thistle (Kali tragus). The United States Fish and Wildlife Service had recommended the plant be removed from the endangered species list.[7] (link added by Mary Ann Machi)