As plant species are increasingly threatened with extinction due to habitat disruption, conservationists recognize the growing importance of site-specific information to species preservation. This volume presents 27 papers based on lectures and discussions at a symposium held at The New York Botanical Garden. The need for current information on populations of rare or endangered plants is emphasized. Also included are comprehensive guidelines for the preparation of status reports on rare or endangered plants, the text of the U.S. Endangered Species Act and amendments, and copies of pertinent federal agency policy statements.