In botany, stipule refers to outgrowths borne on either side of the base of a leafstalk (or 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. A relationship exists between the anatomy of the stem node and the presence or absence of stipules. Most plants with trilacunar nodes have stipules; species with unilacunar nodes lack stipules (Sinnott and Bailey, 1914, cited in Esau, 1953).

Image:Rosa canina blatt 2005.05.26 11.50.13.jpg|Leafy stipules at the base of a Rose leaf (Rosa canina) Image:E didieroides ies.jpg|Stipular spines accompanied by prickles of Euphorbia didieroides Image:N Prop S0162.JPG|Stipular spines on the mesquite tree (Prosopis pallida)]] Image:E pteroneura ies.jpg|Glandular stipule of Euphorbia pteroneura Image:Carpinus betulus ies.jpg|Stipules protecting young leaves of Carpinus betulus (European Hornbeam) Image:Alchemilla mollis ies.jpg|Fused together and leaf-like stipules of Alchemilla mollis Image:Jatropha spicata ies.jpg|Stipules building glandular hairs on Jatropha spicata Image:Monadenium spectabile ies.jpg|Stipular spine clusters of Monadenium spectabile

References

• Esau, K. 1953. Plant Anatomy. Second Edition. John Wiley & Sons, Inc., New York, London, Sidney. 767 pp.
• Sinnott, E. W. and I. W. Bailey. 1914. Investigations on the phylogeny of the angiosperms. 3. Nodal anatomy and the morphology of stipules. Amer. J. Bot.,1: 441-453.

plant morphology

Palist | Stipule | Steunblaadje | Лисни залисци