Page author: David Giblin
Alnus incana
mountain alder
WTU specimens
Other herbaria

Distribution: Occurring east of the Cascades crest in Washington; Alaska south to New Mexico, also in the north-central and northeastern region of North America.

Habitat: Moist places, streamside, low to high elevations.

Flowers: March-May

Origin: Native

Conservation Status: Not of concern

Description:
General:

Monoecious, deciduous shrubs 2 to 10 m. tall, the bark grayish-brown to reddish, the new growth usually downy-puberulent.

Leaves:

: Leaves alternate, simple, the blades broadly elliptic to ovate-oblong, 3-7 cm. long, rounded at the base and usually obtuse at the tip, the margins wavy and denticulate, the upper surface green, often glabrous, the lower surface pale, usually pubescent.

Flowers:

Catkins developing before the leaves on growth of the previous season; staminate catkins clustered, pendulous, 3-10 cm. long, the flowers consisting of 4 subsessile anthers; pistillate catkins cone-like, ellipsoid-ovoid, 9-13 mm. long, the peduncles stout, short.

Fruits:

Nutlet thin-margined but without a true wing.

Accepted Name:
Alnus incana (L.) Moench
Publication: Methodus. 424. 1794.

Synonyms:
(none provided)
Infraspecies:
ssp. tenuifolia – mountain alder
Additional Resources:

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

WA Flora Checklist: Alnus incana checklist entry.

E-Flora BC: Alnus incana atlas page.

CalPhotos: Alnus incana photos.

USDA Plants: Alnus incana information.

35 photographs:
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