Virginia Tech Dendrology

Italian alder Betulaceae Alnus cordata (Loisel.) Duby symbol: ALCO13
Leaf: Alternate, simple, alternate, broadly ovate, heart-shaped base, 2 to 4 inches long, finely serrate, dark green and shiny above, paler with a few scattered brown hairs below particularly in vein axils and along midrib.
Flower: Species is monoecious; males are yellow-green elongated catkins about 2 to 3 inches long, in hanging clusters; females are upright, small (1/4 inch) and reddish green, appearing in early spring.
Fruit: Cone-like, woody, 1 inch long, green but turning reddish brown when ripe, contains numerous small winged seeds, ripen in early fall and persist through the winter.
Twig: Slender, olive green, slightly sticky when young, light colored lenticels; buds are stalked, green turning red and 1/4 inch long.
Bark: Young bark a greenish gray with numerous lenticels, often appearing blistered; later becoming a light gray-brown with shallow fissures and flat ridges.
Form: Medium sized upright tree reaching up to 60 feet tall with a narrow crown.
Looks like: European black alder - red alder - Arizona alder

Additional Range Information: Alnus cordata is planted in the USDA hardiness zones shown above and is not known to widely escape cultivaton. Download the full-size PDF map.
External Links: USDA Plants Database
All material 2021 Virginia Tech Dept. of Forest Resources and Environmental Conservation; Photos and text by: John Seiler, Edward Jensen, Alex Niemiera, and John Peterson; Silvics reprinted from Ag Handbook 654; range map source information