Stems, of various sizes and shapes, are involved in most of the organic processes and interactions of plants, ranging from support, transport, and storage to development and protection. The stem itself is a crucially important intermediary: it links above- and below ground organs-connecting roots to leaves. An international team of leading researchers vividly illustrate that stems are more than pipes, more than simple connecting and supporting structures; rather stems are critical, anatomically distinct structures of enormous variability. It is, to an unappreciated extent, this variability that underpins both the diversity and the success of plants in myriad ecosystems. Plant Stems will be a valuable resource on form/function relationships for researchers and graduate-level students in ecology, evolutionary biology, physiology, development, genetics, agricultural sciences, and horticulture as they unravel the mechanisms and processes that allow organisms and ecosystems to function. Syntheses of structural, physiological, and ecological functions of stems Multiple viewpoints on how stem structure relates to performance Highlights of major areas of plant biology long neglected