The aim of this book is to explore how plants function, grow, reproduce, and evolve within the limits set by their physical environment. It was written in the firm belief that organisms cannot violate the laws of physics and chemistry and that knowing how these laws operate and confine the organic expression of size, form, and structure is essential to understanding biology. This perspective is shared by a number of disciplines physiology and ecology to name just two and traces its conceptual roots to the principal concerns of early comparative morphologists and anatomists. It differs only slightly from the bulk of biology by its emphasis on using the principles of physics and engineering to answer fundamental questions about the relation between form and function, but it clearly defines the intellectual scope of what has become known as biomechanics a discipline that operates at the interface between engineering and biology.