Alder, Black – Alnus glutinosa
Found in these areas: Marsha Area
European Black Alder, a native species of Europe, western Asia, and northern Africa, is also known as Common Alder or Black Alder. It has been widely planted in the U.S. and has become naturalized in many areas of eastern North America. In 2003 a European Black Alder in the Arboretum’s Marsh Area was listed as a Tennessee State Champion Tree based on its girth, height, and crown. This tree subsequently died and has been removed.
European Black Alder is used for reclamation of strip mines because it grows rapidly and helps control erosion. Its nitrogen-fixing root nodules and abundant leaf litter improve soil fertility. It provides cover and a dependable food source for seed-eating birds during the winter. Alder wood has been used for timber, as fiber for paper and particle board, in joinery as solid wood or veneer, and for fuel wood.
The glossy, dark green leaves of European Black Alder are broadly ovate to obovate (broadest above the middle) in shape. The sticky leaves and twigs give rise to the species name “glutinosa.” The male catkins form in the fall and persist during the winter. The female catkins develop in late winter, and the inconspicuous flowers bloom before leaf emergence. Woody cones develop during the summer with seeds being dispersed in the fall. The cones persist throughout the winter months. As with other species of alder, European Black Alder does well on wet sites such as stream banks and wetland situations, but it can also grow on drier sites where the soils are infertile.