Alnus alnobetula
Common name: 
Circumpolar alder group
AL-nus al-no-BET-u-la
Alnus viridis
Native to (or naturalized in) Oregon: 
  • Broadleaf, deciduous shrub, spreading to compact, to over 32 ft (10 m). Bark smooth: lenticels scattered. Winter buds ovoid, directly attached without a supporting stalk (sessile). Leaf blade broadly to narrowly ovate or elliptic, 3–11 × 3–8 cm, base rounded, obtuse to nearly cordate, margins minute toothed to coarsely doubly serrate, apex acute to rounded.  Male catkins singular or in clusters of 2–4, formed late in the growing season before flowering and exposed during winter; female catkins singular or in clusters of 2–10, formed in season before blooming, exposed with new growth in spring.  Fruit (samaras) elliptic to obovate, wings wider than body, membranaceous. (Adapted from Flora of North America)
  • Native distribution: Circupolar; Southern arctic, subarctic, and northern mountainous regions in North America, Europe and Asia.  Found throughout Canada and in most northern states of the US as well as in mountainous regions in California,Tennessee, and North Carolina.
  • Alnus alnobetula: subspecies in North America (Flora of North Amereica)
  • alnobetulaalno-, Alnus (alder) and Betula (birch), both genera are in the Birch family (Betulaceae)
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