Page author: David Giblin
Alnus viridis
green alder, mountain alder

Distribution: Widely distributed throughout the mountainous areas of Washington; Alaska south to California, east across the northern half of North America to the Atlantic Coast.

Habitat: Moist areas, low to high elevations.

Flowers: May-July

Origin: Native

Conservation Status: Not of concern


Monoecious, deciduous shrubs mostly 2-4 m. tall, the bark reddish-brown, becoming grayish-black, the young growth glabrous but with sessile glands.


Leaves alternate, simple, the blades narrowly to broadly ovate, 3-10 cm. long, the base rounded, the tip pointed, the margins wavy and once or twice finely denticulate, the blades only slightly paler beneath, glabrous except for the main veins, the petioles glabrous.


Catkins developing on growth of the current season; staminate catkins pendulous, up to 10 cm. long; pistillate catkins cone-like, 3-6 per branch, ovoid-ellipsoid, 1.5 cm. long and half as thick, on slender peduncles up to 3 times as long as the catkin.


Nutlet with thin, membranous wings half as broad as the nutlet.

Accepted Name:
Alnus viridis (Chaix) DC.
Publication: Fl. France, ed. 3. 3: 304. 1805.

Synonyms & Misapplications:
(none provided)
ssp. fruticosa – Siberian alder
ssp. sinuata – mountain alder, Sitka alder    Alaska to northern California, east through Washington and Oregon to Montana
Additional Resources:

PNW Herbaria: Specimen records of Alnus viridis in the Consortium of Pacific Northwest Herbaria database.

WA Flora Checklist: Alnus viridis checklist entry.

E-Flora BC: Alnus viridis atlas page.

CalPhotos: Alnus viridis photos.

USDA Plants: Alnus viridis information.

54 photographs:
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