The function of the epidermis in plants is primarily to protect against environmental stresses and reduce water loss. As the outermost layer of cells, the epidermis serves as a barrier to pathogens and physical damage while regulating gas exchange through specialized structures called stomata. Additionally, the epidermis often secretes a waxy cuticle that aids in minimizing water evaporation, particularly in arid conditions. This protective role is vital for maintaining plant health and optimizing photosynthesis, which is essential for their survival.