Tobacco leaf. Light micrograph of a transverse section through a leaf of the tobacco plant, Nicotiana tabacum. At top, a white cuticle is seen forming a protective coating on the upper surface of the leaf. Beneath it is a layer of epidermal cells. Two tissue types make up the inner leaf anatomy: palisade tissue (green) consists of tightly packed cells containing many chloroplasts for photosynthesis; spongy mesophyll tissue consisting of loosely arranged cells with fewer chloroplasts. Between these tissues are two leaf veins (blue). On the undersurface of the leaf is a layer of epidermal cells, some forming leaf hairs. Magnification: x40 at 35mm size.