Intended for undergraduate and graduate courses in plant development, this book explains how the cells of a plant acquire and maintain their specific fates. Plant development is a continuous process occurring throughout the life cycle, with similar regulatory mechanisms acting at different stages and in different parts of the plant. Rather than focussing on the life cycle, the book is structured around these underlying mechanisms, using case studies to provide students with a framework to understand the many factors, both environmental and endogenous, that combine to regulate development and generate the enormous diversity of plant forms.