This book is the first compendium to present the variability of macroscopic and microscopic petiole structure. It contains more than 190 species of pteridophytes, conifers and angiosperms with distinct life forms (herbs, shrubs and trees). The first part of the book explains with microphotographs the most important structural variation of petiole vascular system, and elucidates the ecophysiological functions and the ontogeny of petioles. This book also includes a list of morphological and anatomical features based on photographs designed to facilitate the caracterization of petiole structure and to assist at ecological interpretations. It incorporates a description of each species that first characterizes the plant habit and macroscopic aspects, and it is followed by the microscopical features of epidermis, cortex and vascular system. The descriptions include photographs from the leaves and cross-sections of the middle region of the petioles, which are based on double-staining technique that reveals unlignified and lignified tissues.
The book appeals to scientists in the fields of plant morphology, anatomy and ecology, and to students interested in knowing the diversity of petioles.