The U.S. Endangered Species list, maintained by the U.S. Fish and Wildlife Service, includes plant and animal species identified as endangered or threatened under the U.S. Endangered Species Act of 1973 (ESA; 16 U.S.C. § 1531 et seq.). An endangered species is in danger of extinction through all or part of its range. A threatened species is likely to become endangered in the near future. Candidate species are under consideration for listing; the review process is extensive. Some of the process is described in this Endangered Plants Brochure.
NatureServe is a U.S. non-profit organization that maintains detailed listings of the conservation status of animal, plant, and fungus species. Conservation organizations including the South Carolina DNR and the IUCN use NatureServe ranks to classify species. Ranks include a letter and a number. The letters – G, N, and S – denote Global, National, or Subnational Status. Numbers from 1 to 5 describe degree of endangerment, from critically imperiled to secure.
South Carolina has its own list of rare, threatened, and endangered species. This list is maintained by the SC Department of Natural Resources. It ranks state species by global and state status, including ESA status, NatureServe global conservation status, and state rank, which is based on NatureServe National (N) and Subnational (S) Conservation Status.
The IUCN Red List of Threatened Species, maintained by the International Union for Conservation of Nature, is a list of the biological species threatened with extinction worldwide. It includes over 19,000 plant species, many of them also listed on the U.S. Endangered Species list. Categories of endangerment include Extinct, Extinct in the Wild, Critically Endangered, Endangered, and Vulnerable. The Near Threatened category is for species that are likely to become vulnerable in the near future. Many species on the list are classified as Least Concern, at fairly low risk.