stipule

One of a pair of leaflike structures, spines, glands, or scales at the leaf base or along a petiole. Stipules are believed to protect the developing leaf in the embryonic state. They may occasionally be modified to enclose a bud, as in beeches (Fagus). Large green stipules are seen in the garden pea (Pisum sativum) and replace photosynthetic tissues lost by the modification of the leaflets into tendrils.