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Alnus incana (L.) Moench
Gray alder, Speckled alder
USDA Symbol: alin2
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.
Bloom InformationBloom Time: Mar , Apr , May
, WY Canada: AB
, SK Native Distribution:
Lab. to AK,
s. to NJ,
mts. of WV,
n.e. IA, MN,
& w. mts. to NM
& c. CA Native Habitat:
Wetlands & stream edges
Growing ConditionsWater 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.
BenefitUse 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
PropagationDescription: 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
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
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:
- Johnstown, PA
Record Last Modified: 2012-06-30
Research By: TWC Staff