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Alnus incana (Gray alder)
Smith, R.W.

Alnus incana

Alnus incana (L.) Moench

Gray alder, Speckled alder

Betulaceae (Birch Family)

Synonym(s):

USDA Symbol: ALIN2

USDA Native Status: L48 (N), AK (N), CAN (N), SPM (N)

Speckled alder is a tall shrub or small tree, 20-35 ft. tall, with multiple, crooked, leggy trunks. Bent in a wide curve at their base, the trunks become upright and picturesque. Deciduous leaves are rounded and coarsely toothed, remaining dark-green in autumn. The flower is a purplish-red catkin and the fruit is a woody cone.

This is the common alder throughout the Rockies.

 

Plant Characteristics

Duration: Perennial
Habit: Shrub , Tree
Leaf Retention: Deciduous
Leaf Arrangement: Alternate
Leaf Complexity: Simple
Leaf Shape: Elliptic , Ovate
Leaf Venation: Pinnate
Leaf Margin: Double-serrate
Leaf Apex: Acuminate , Acute , Obtuse
Leaf Base: Cuneate , Rounded
Breeding System: Flowers Unisexual , Monoecious
Size Notes: Height to 25 M.
Leaf: Green
Flower:
Fruit:
Size Class: 12-36 ft.

Bloom Information

Bloom Time: Mar , Apr , May

Distribution

USA: AK , AZ , CA , CO , CT , IA , ID , IL , IN , MA , MD , ME , MI , MN , MT , ND , NH , NJ , NM , NV , NY , OH , OR , PA , RI , UT , VA , VT , WA , WI , WV , WY
Canada: AB , BC , MB , NB , NL , NS , ON , PE , QC , SK
Native Distribution: Lab. to AK, s. to NJ, mts. of WV, n.e. IL, n.e. IA, MN, n.e. ND & w. mts. to NM & c. CA
Native Habitat: Wetlands & stream edges

Growing Conditions

Water Use: High
Light Requirement: Sun , Part Shade , Shade
Soil Moisture: Moist , Wet
Soil pH: Circumneutral (pH 6.8-7.2)
CaCO3 Tolerance: Low
Soil Description: Wet soils.
Conditions Comments: Alnus rugosa and Alnus tenuifolia are usually considered subspecies. Fast-growing and flood tolerant, this species is short-lived, rarely exceeding 40 years. It can be thicket-forming and provides erosion control along watercourses in the mountains. Alders fix nitrogen and thus serve as nutrient-giving pioneers in reclamation projects.

Benefit

Use Wildlife: Songbirds, waterbirds, and mammals frequently use this species.
Use Other: The Navajo Indians made a red dye from the powdered bark.
Interesting Foliage: yes

Propagation

Description: Seeds of most alders germinate when they are fresh without pretreatment.
Seed Collection: Not Available
Seed Treatment: If seeds have dried in storage, a cool-moist stratification at 41 degrees for 180 days will be necessary.
Commercially Avail: yes

Find Seed or Plants

View propagation protocol from Native Plants Network.

Mr. Smarty Plants says

Alder native to Central Indiana
May 30, 2006
I am trying to find out whether there exists a plant named Alnus rugosa. I bought a plant recently that said Speckled Alder, Alnus serrulata (rugosa), but have been unable to determine if this is a c...
view the full question and answer

National Wetland Indicator Status

Region:AGCPAKAWCBEMPGPHIMWNCNEWMVE
Status: FACU FAC FACW FACU FACW FACW FACW FACW
This information is derived from the U.S. Army Corps of Engineers National Wetland Plant List, Version 3.1 (Lichvar, R.W. 2013. The National Wetland Plant List: 2013 wetland ratings. Phytoneuron 2013-49: 1-241). Click here for map of regions.

From the National Organizations Directory

According to the species list provided by Affiliate Organizations, this plant is either on display or available from the following:

Natural Biodiversity - Johnstown, PA

Additional resources

USDA: Find Alnus incana in USDA Plants
FNA: Find Alnus incana in the Flora of North America (if available)
Google: Search Google for Alnus incana

Metadata

Record Last Modified: 2012-06-30
Research By: TWC Staff

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