In the third edition of this very successful textbook, the author describes a practical approach to the important physiological and ecological factors that determine the survival of the green plant. The book has been extensively rewritten to keep abreast of recent discoveries. Much more information on the growth and development of plants is included to stress that the survival of a plant species may depend on all stages of the plant's life cycle. Practical techniques are described to show how many of the ideas discussed can easily be investigated. The book is therefore very useful for project work as well as class practicals in both schools and introductory biology and botany courses at university.