1997 IUCN Red List of threatened plants
This represents the most comprehensive compilation of data on threatened vascular plants ever published. It includes the names of some 33,000 plant species determined to be rare or threatened on a global scale. Conservation assessments were provided by the IUCN Species Survival Commission, the National Botanical Institute (South Africa), Environment Australia and CSIRO,. The Nature Conservancy, the Smithsonian Institution, and the Royal Botanic Gardens, Kew together with hundreds of botanic gardens and botanists throughout the world.