Black Alder (Alnus glutinosa)

Black Alder is a multi-trunked tree with sticky young twigs and obovate to round glossy dark green leaves. This tree produces male catkins that develop in the fall and persist through the winter months and female catkins that develop in late winter to spring. The female catkins then develop into 3/4″ long cones. Nitrogen-fixing microorganisms develop in the nodules of the roots making Black Alder an excellent tree to plant in heavily disturbed areas and acid sites such as coal strip-mines. It can also be used as internal orchard windbreaks. Black Alder is also useful in rain gardens, low and moist sites, and dry sites with poor soils.

INTRODUCED

Map courtesy of the USDA-NRCS Plant Database.