Alnus glutinosa Betulaceae
Common Alder, European Alder, Black Alder
- Broadleaf deciduous tree to 65 ft (20 m) tall or, rarely, more, often multistemmed, open crown. Bark brown-black. Twigs covered with glutinous glands, smooth. Leaves simple, alternate, 4-10 cm long, broad subovate to orbicular, apex rounded, base acuminate, margins coarsely and doubly serrate, dark green above, paler below, petiole 1-2.5 cm. Male catkins in clusters of 3-5, each 5-10 cm long, seed catkins (cones) 1-2 cm long, ovoid, long stalked.
- Sun part shade. Apparently not to fussy about soil, tolerates dry soils, but is best in moist or even wet soils.
- Hardy to USDA Zone 4 Native to Europe to the Caucasus and Siberia. A nitrogen fixer. Several cultivars available, including 'Laciniata', which has deeply dissected leaves.
- glutinosa: sticky, the young leaves and stems
- Oregon State Univ. campus: southwest of Education Hall, along service road.