In the past 20 years there has been a revolution in plant sciences as new methods of molecular biology and biophysics have been applied to investigate environmental stress particularly desiccation tolerance. Today there is a good level of understanding of how plant cells cope with extreme water stress. This book is divided into four sections dealing with 1) the technical background to desiccation tolerance studies 2) the frequency and levels of dehydration stress tolerance in biological systems 3) mechanisms of damage and tolerance and 4) a brief prospect and retrospect. It covers orthodox and recalcitrant seeds pollen and spores vegetative parts and other plant tissues.