Thorns, spines, and prickles

In plant morphology, thorns, spines, and prickles, and in general spinose structures (sometimes called spinose teeth or spinose apical processes), are hard, rigid extensions or modifications of leaves, roots, stems, or buds with sharp, stiff ends, and generally serve the same function: physically defending plants against herbivory. == Description == In common language, the terms are used more or less interchangeably, but in botanical terms, thorns are derived from shoots (so that they may or may not be branched, they may or may not have leaves, and they may or may not arise from a bud), spines are derived from leaves (either the entire leaf or some part of the leaf that has vascular bundles inside, like the petiole or a stipule), and prickles are derived from epidermis tissue (so that they can be found anywhere on the plant and do not have vascular bundles inside).

Source: Wikipedia — Thorns, spines, and prickles (CC BY-SA 4.0)