Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Plant morphology (or phytomorphology) is the general term for the study of the morphology (physical form and external structure) of plants. This is usually considered distinct from plant anatomy, which is the study of the internal structure of plants, especially at the microscopic level. Plant morphology is useful in the identification of plants. Plant morphology "represents a study of the development, form, and structure of plants, and, by implication, an attempt to interpret these on the basis of similarity of plan and origin." There are four major areas of investigation in plant morphology, and each overlaps with another field of the biological sciences.