The term "leaf margin" refers to the edge or border of a leaf. It can vary significantly among different plant species, influencing both the leaf's appearance and its function. Common types of leaf margins include smooth (entire), serrated (toothed), and lobed. These variations can help in identifying plants and understanding their adaptations to the environment. Leaf margins play a role in water retention and gas exchange. For instance, smooth margins may reduce water loss, while serrated margins can help in capturing moisture from the air. The shape and structure of a leaf's margin are important for its overall health and survival in various habitats.