The cells of the epidermis can vary in the way they are made and how they work. Most plants have an epidermis that is a single cell layer thick. Some plants, however, have an epidermis with more than one layer. Epidermal cells are linked tightly to each other. They give strength and protection to the plant. In the parts of the plant that are above ground, the epidermal cells contain cutin and are covered with a cuticle. This cuticle reduces loss of water. It is sometimes covered with wax. The wax gives some plants a whitish or bluish surface color. It also protects the plant from sunlight and wind. 