The rationale for this three-volume work covering nearly 250 major sites for conservation of plant diversity worldwide is concern about rapid global loss and degradation of natural ecosystems. By highlighting areas of prime botanical importance, it is hoped that their conservation will be ensured by an adequate commitment of resources. Selection of the sites is based both on floristic statistics and on detailed first-hand knowledge of numerous botanists. The data sheet for each site includes regional context, and outlines wider patterns of plant distributions, threats and conservation efforts; additional sites are also mentioned. This work will be essential reading for all those concerned with planning land use strategies for conservation and appropriate development. It is WWF and IUCN's hope that this global assessment will be followed by further assessments at the local level, so that the vital task of conservation of plant diverstiy can be well integrated in detail into national and regional conservation and development strategies.