What is the primary purpose of stipules?

Stipules are small, leaf-like structures that are found at the base of the leaf petiole in many plants. Their primary function is to protect the developing buds and young leaves that emerge from the axil between the stipule and the stem. This protective role is crucial because young tissues are often delicate and vulnerable to damage from herbivores, environmental conditions, or pathogens. In some cases, stipules may also help in the photosynthesis process, albeit not as their main function, and may even assist in storing water or nutrients, but their defining characteristic is primarily protective. Therefore, the answer regarding their protective function aligns with the biological role they play in various plant species.