Human skin and the waxy covering of some plants are examples of the epidermal tissue. In humans, the epidermis is the outermost layer of the skin composed of keratinized epithelial cells that provide a protective, water-resistant barrier. In plants, the epidermis is the outer layer of cells covering leaves and stems, which secretes a waxy substance called the cuticle to protect against water loss and environmental damage. Thus, both human skin and the waxy covering of plants serve as protective surfaces formed by epidermal tissue to regulate interaction with the environment. This tissue type is specialized for protection and barrier functions in both organisms.