Definition: Stipules

A stipule refers to outgrowths borne on either side of the base of a leafstalk (the petiole). A pair of stipules is considered part of the anatomy of the leaf of a typical flowering plant, although in many species the stipules are inconspicuous or entirely absent (and the leaf is then termed exstipulate).

Stipules are morphologically variable and might appear as glands, scales, hairs, spines, or laminar (leaf-like) structures.