Gossypium herbaceum L var africanum (Watt) Hutch and Ghose. It is one of the wild cotton taxa detected in desert of Siwa oasis - Egypt. It is one of the ancestors of Egyptian cotton (G. barbadense). This study is the first detailed study carried out on this variety. This study focused on the physiological and molecular characters related to the drought tolerance. This book will be useful for plant ecologists, plant physiologists and plant breeder scientists.