When stipules abscise, a stipular scar develops. Although nobody has counted, probably less than a quarter of all known angiosperm species have stipules. Among the dicotyledons, stipules have been observed in approximately 140 families, although in nearly half of these only relatively few species possess stipules. There are many groups of angiosperms in which stipules have never been reported, so that when stipules are observed, they often help an investigator to guess its home family. Euphorbiales have stipules.
Stipules are uncommon among the monocotyledons, where they tend to be small and vestigial.
Conspicuous stipules covering buds also can be observed in Cunonia capensis . However, the majority of angiosperms living today show no disadvantage by lacking them, and in many the stipule is small and vestigial, without any obvious function. There are a number of interesting functions demonstrated for stipules of certain plant species. Plant biologists have assumed that green stipules are photosynthetic, but ecophysiologists generally have not determined how significant green stipules may be as temporary or persistent photosynthetic structures. Anatomical reports on photosynthetic stipules are exceedingly rare, so that we know little about the presence of stomates and the nature of the mesophyll in stipules.