The rationale for this work covering nearly 250 major sites for conservation of plant diversity 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. Each site's Data Sheet includes regional context, and outlines wider patterns of plant distributions, threats and conservation efforts; additional sites are also mentioned.This work is essential reading for all those concerned with planning land use strategies for conservation and development. WWF and IUCN hope that this global assessment will be followed by further local assessments, so that the vital task of conservation of plant diversity can be well integrated into national and regional conservation and development strategies.