Alnus glutinosa
Common name: 
Common Alder
European Alder
Black Alder
AL-nus glu-ti-NO-sa
Native to (or naturalized in) Oregon: 
  • 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 (pollen) catkins are in clusters of 3-5, each 5-10 cm long; female (seed) catkins when mature are cone-like, 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: on both sides of the short service road leading to Pharmacy and Furman Hall.
Click image to enlarge
  • flower clusters and cones, spring

    flower clusters and cones, spring

  • plant habit

    plant habit

  • leaves


  • leaves


  • cones and leaves

    cones and leaves

  • trunk, bark

    trunk, bark

  • plant habit, winter

    plant habit, winter

  • winter twigs; catkins, cones and buds

    winter twigs; catkins, cones and buds