Smooth alder is a type of tree commonly found in wetlands and riparian forests. Synonyms for smooth alder include Alnus serrulata, Alnus rhombifolia, and Alnus incana. Smooth alder is known for its smooth, gray bark and simple, serrated leaves. It produces small, cone-like fruits that are an important food source for various birds and mammals. Smooth alder is also valued for its wood, which is used for furniture, cabinetry, and pulp. In addition to its practical uses, smooth alder is also appreciated for its ornamental beauty, with its foliage turning a vibrant yellow in the autumn.