: straw, stalk) is a term coined by Linnaeus
which 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. 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).
Types of Stipules
- 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.