This third edition provides the basics for introductory courses on plant physiology without sacrificing the more challenging material sought by upper division and graduate level students. The text contains many new or revised figures and photographs, all in full colour. A website, referenced throughout the text, includes additional study questions, WebTopics (elaborating on selected topics discussed in the text), WebEssays (discussions of cutting edge research topics, written by those who did the work) and additional suggestions for further reading. Key pedagogical changes to the text result in a shorter book. Advanced material from the second edition has been removed and posted at an affiliated website, while many new or revised figures and photographs, study questions and a glossary of key terms have been added. Despite the streamlining of the text, the third edition incorporates all the important developments in plant physiology, especially in cell, molecular and developmental biology.