These dark areas are called maria. They are thought to be formed by volcanic eruptions in the moon's history.hope this helped:)
Answer: Helps the plant breathe: The epidermis of the leaf contains guard cells that control and regulate the small pores on the undersurface of the leaves. These pores are called stomata. Stomata are responsible for regulating water in and out of the cell. It is also responsible for the exchange of gases across the epidermis.