Part I INTRODUCTION; Chapter 1 HISTORY OF BOTANICAL INVESTIGATIONS IN EASTERN SAUDI ARABIA; Chapter 2 GEOGRAPHICAL AREA OF THE FLORA: TOPOGRAPHY AND SUBUNITS; Chapter 3 THE CLIMATE OF EASTERN SAUDI ARABIA; Chapter 4 EASTERN SAUDI ARABIA IN THE PLANT-GEOGRAPHICAL REGIONS OF THE MIDDLE EAST; Chapter 5 PALEOENVIRONMENTS AND DEVELOPMENT OF THE EAST ARABIAN FLORA; Chapter 6 THE VEGETATION: PHYSIOGNOMY AND PLANT COMMUNITIES; Part II THE FLORA; Chapter 7 EXPLANATORY NOTES; Chapter 8 SYSTEMATIC ACCOUNT OF THE FLORA;.