RARE AND ENDANGERED PLANTS
RARE AND ENDANGERED PLANTS. In the late 1960s and early 1970s, concern over the state's dwindling natural resources led to the establishment of such organizations as the Rare Plant Study Center and the Texas Organization for Endangered Species to document the rare plants of Texas. Natural area surveys, conducted by a multidisciplinary team of scientists, began in 1973 with the support of the Lyndon Baines Johnson School of Public Affairs and the Texas Parks and Wildlife Department. The federal Endangered Species Act of 1973 provides protection for rare plants and animals. In 1974 the Rare Plant Study Center distributed its most comprehensive list of 500 plants considered to be rare in Texas. (Most plants on such lists are endemics, plants found only within a certain region.) Around this time the TOES began listing plants thought to be rare in the state. In 1975 the United States became a party to the Convention on International Trade in Endangered Species of Wild Fauna and Flora. The convention prevents selected plants, including the entire cactus and orchid families, from being traded internationally without permits. In 1975 the United States Fish and Wildlife Service was charged with carrying out the Endangered Species Act and adopted the Smithsonian Institution's "Report on Endangered and Threatened Plant Species of the United States." The report listed 239 Texas plants, approximately 5 percent of the state's vascular flora. The United States Fish and Wildlife Service Region 2 office in Albuquerque contracts with various individuals and agencies to report on candidate plants. These status reports contribute to the decision to list plants as endangered or threatened. When such a decision is made, a summary of the plant's distribution and biology is published in the federal register for a period of public comment and review. Once a plant is listed, a recovery plan is developed with the intention of bringing the plant back to such a level of incidence that it can be removed from the list.
In 1978 Texas wild rice (Zizania texana) became the first Texas plant to be federally listed as endangered. Two cacti, bunched Cory cactus (Coryphantha ramillosa) and Lloyd's Mariposa cactus (Neolloydia mariposensis) were listed as threatened in 1979, and six others-Tobusch fishhook cactus (Ancistrocactus tobuschii), Nellie Cory cactus (Coryphantha minima), Sneed pincushion cactus (Coryphantha sneedii var. sneedii), Lloyd's hedgehog cactus (Echinocereus lloydii), black lace cactus (Echinocereus reichenbachii var. albertii), and Davis's green pitaya (Echinocereus viridiflorus var. davisii)-were listed as endangered. Because of the enormous task of evaluating candidate plants and recovery plans, the United States Fish and Wildlife Service Region 2 office established plant recovery teams for each state in the region, as well as the Texas Plant Advisory Board, in 1980. In 1981 the Texas poppy-mallow (Callirhoë scabriuscula ) was listed as endangered. Also in 1981 legislation modified the Texas Parks and Wildlife Code to include plants in the state endangered-species law. McKittrick pennyroyal (Hedeoma apiculatum) was listed as threatened, and Navasota ladies'-tresses (Spiranthes parksii) was listed as endangered in 1982. TOES published a list of thirty-four endangered plants in 1982.
In late 1983 the Texas Natural Heritage Program was initiated as a joint venture of the General Land Office and the Nature Conservancy. The botanical component of the program developed a list of about 250 plants rare in Texas and the world and a list of about 300 peripheral or disjunct plants rare in Texas. (Plants that are rare within an area yet common elsewhere are termed peripheral-at the edge of their natural range-or disjunct-beyond their normal range.) These lists are based on number of populations, threats to survival, and many other criteria. The lists are constantly updated, and computerized and manual files are maintained on each plant. TOES revised its list in 1983, raising its total number of plants listed to forty-four. Rare plants may be saved from extinction through habitat preservation or (as a last resort) cultivation. Private organizations such as the Nature Conservancy and governmental agencies such as the Texas Parks and Wildlife Department, the National Park Service, and the United States Fish and Wildlife Service purchase land or negotiate conservation agreements with landowners to protect endangered species. In 1984 the San Antonio Botanical Center was designated by the Center for Plant Conservation as the primary institution in Texas for propagating and maintaining rare plants. In 1984 ashy dogweed (Dyssodia tephroleuca), Johnston's frankenia (Frankenia johnstonii), and Texas snowbells (Styrax texana) were added to the federal endangered list.
In 1985 TOES added plant communities to its review of rare plants and animals. By September 1985 the United States Fish and Wildlife Service listed 12 Texas plants as endangered, 3 as threatened, 18 waiting to be listed or probably extinct, 108 awaiting further study, and 151 no longer being considered for listing. The state endangered species law was amended in 1985 to provide more protection for endangered and threatened plants not found on federal or state land. In late 1985 the Texas Parks and Wildlife Department began developing an identification manual on the endangered and threatened plants of the state for use by law enforcement agencies to enforce the endangered species law. As the human population grows and more habitat is altered to meet man's requirements, more plants will become rare and perhaps endangered. Groups such as the National Wildflower Research Center and the Native Plant Society of Texas can help protect them. See also HERBARIA.
Edward S. Ayensu, and Robert A. DeFilipps, Endangered and Threatened Plants of the United States (Washington: Smithsonian, 1978). Endangered Species Act of 1973 (Washington: GPO, 1974). Rare and Endangered Plants Native to Texas (Rare Plant Study Center, University of Texas at Austin, 1974).