Status of endangered and threatened plant species on Nevada Test Site: a survey. Part 2. Threatened species

This is the second of a two-part study of plant species on the Nevada Test Site (NTS) that are listed as possibly threatened or endangered by the U.S. Fish and Wildlife Service (FWS). This study was undertaken as a response by DOE to comply with the Endangered Species Act of 1973 (the Act). Part 1 treated species listed under terms of the Act as proposed endangered species. Part 2 primarily treats those species listed as threatened species candidates. Among the 15 species that grow on NTS and appeared in the Federal Register lists of candidate threatened species we report three: Astragalus funereus, Coryphantha vivipara var. rosea, and Gilia ripleyi, that should be considered as threatened. Two other species which occur on NTS and were not included on either the threatened or endangered lists should also be classified as threatened: Penstemon thurberi var. anestius and Sclerocactus polyancistrus. Of the 12 other species originally listed in the Federal Register, eight are of sufficient interest to warrant continued monitoring under a category we suggest as ''Plants of Special Concern.'' The other four do not appear to require any protective measures or surveillance at this time. We suggest critical habitats for those species recommended for threatened status and note that some suggested critical habitats may serve for more than one species and may also include habitats for some species of special concern. Updated information about species covered in Part 1 suggests that Trifolium andersonii var. beatleyae, earlier considered endangered, should now be recommended to be removed from endangered or threatened status because of more widespread distribution than was known to us at the time Part 1 was published.