This is the first volume in a six-part series which charts the flora of the Arabian Peninsula and the Socotran archipelago. It covers all native flowering plants and ferns as well as major cultivated and amenity plants of Saudi Arabia, Yemen, the Sultanate of Oman, United Arab Emirates, Qatar, Bahrain and Kuwait. The first part of this volume gives an introduction to topology and geology, climate, vegetation, floristics, phytogeography and conservation. Part two begins the systematic study of the flora. Each species is separately mapped with notes on ecology and distribution. Illustrations and keys are provided to aid identification. Each volume describes around 700 species and should be valuable to non-specialists and professionals alike. Volumes 1-4 of this series cover the dicot families, volume 5 covers the monocot families and volume 6 is a monogrpahic introduction. The family order follows the Engler and Prantl system.