USEFULNESS AND ECONOMIC-POTENTIAL OF THE RARE PLANTS OF THE UNITED-STATES - A STATISTICAL-SURVEY

The economic usefulness and potential of endangered and rare plants in the United States was surveyed to assess some of the potential implan ts of plant extinction on the world's largest economy. We analyzed rel ationships between an existing comprehensive database of U.S. rare pla nts, and a new database that synthesizes available information on worl dwide plant uses and U.S. crop values. While few rare plants are direc tly useful, nearly 80% of the U.S. plant genera with rare taxa contain at least one useful species. Moreover, two-thirds of the 2949 U.S. ra re and endangered taxa are congeneric with cultivated species. Example s of this close relationship between rare plants and their economicall y significant congenerics were translated into dollar values. For inst ance, the annual U.S. wholesale farm value of food crop congenerics or rare plants is $9 billion. Since many crops require periodic genetic infusions from close relatives to combat threats from climatic change and disease, or to supply features such as improved nutritional value, we conclude that the threats to the rare wild plants of the U.S. also constitute threats to the future of many contemporary crops.