Plant anatomy is a branch of plant morphology which studies the internal structure of plants. The plant body comprises three types of vegetative organs: the root, the stem, and the leaf; and a complex reproductive organ, or assemblage of organs called the flower. Precise separation of the plant into organs is often impossible. Seed plants, in particular, have a highly evolved body with many structural and functional adaptations. Thus, it is difficult to clearly determine which is root, stem, or leaf, as the parts appear to blend into one another. The flower is even more difficult to distinguish and may be interpreted as being a modified shoot system with parts derived from leaves and stem.

There are several types of plant tissue and a number of cell types. One tissue, the epidermis, is composed of epidermal cells, and forms a continuous layer on the surface of...