The Program has maintained a Rare Plant Inventory for nearly 30 years. The print and electronic versions of the Inventory are used by thousands of professional and amateur botanists throughout the state. Consultants and planners preparing environmental documents use the Inventory to determine the potential for resource conflicts and the scope of necessary botanical surveys. Resource managers use the information to guide rare plant protection and the acquisition and management of preserve areas. Conservationists use the same data to review environmental documents and prepare testimony to educate decision-makers.
Researchers use the information to evaluate trends and changes in populations of rare plants.
Approximately 800 of California's most threatened plants are not yet listed under the state and Federal Endangered Species Acts. The Inventory lists are developed through evaluation of existing literature, herbarium collections, and through fieldwork and consultation with local and taxonomic experts. Program staff develop information to support all changes and additions to the Inventory . These changes are then reviewed by a statewide network of over 500 California botanists representing state and Federal agencies, consulting firms, academic institutions, CNPS and other conservation organizations. The Inventory is constantly changing as new data become available and as staff identify additional data that need development.