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Speckled Alder
Alnus incana

A deciduous, thicket-forming shrub or small tree sometimes growing to 16' tall. This species has been planted as an ornamental at water edges. Its root mass prevents erosion on stream banks and enriches soil by making nitrogen available to other plants. Use this plant in restorations, pond edges, and acidic soil conditions.

USDA symbol: ALIN2

General Information

Plant TypeShrub
Height15 to 25 feet
Light ExposurePart Sun, Sun
Soil MoistureMedium
Bloom ColorRed, Yellow
Speckled Alder (Speckled Alder<div><em class="small">Alnus incana</em></div>)
Photo credit: Minnesota Wildflowers (Click to enlarge)

Tolerances

Flooding / Inundation ToleranceHigh
General Resilience6
Salt ToleranceMedium
Stress ToleranceFire Tolerant, General Disturbance

Pollinator Value: Medium

Bloom MonthsMarch to May
Larval Host ofMoths
Specific Pollinators HostedCaloptilia alnicolella, Sthenopis argenteomaculatus

Project Planning

Project TypeErosion Control, Restoration
Coefficient of Conservatism9
Herbivore SensitivityMedium
LifespanPerennial
Rate of SpreadSlow
Soil StabilizationDeep
Vegetative ReproductionClonal

Range

CountyAitkin, Anoka, Becker, Beltrami, Benton, Carlton, Cass, Chisago, Clearwater, Cook, Crow Wing, Dakota, Douglas, Goodhue, Houston, Hubbard, Isanti, Itasca, Kanabec, Kittson, Koochiching, Lake, Lake of the Woods, Mahnomen, Marshall, Mille Lacs, Morrison, Mower, Norman, Otter Tail, Pennington, Pine, Polk, Ramsey, Roseau, Sherburne, St. Louis, Stearns, Todd, Wabasha, Wadena, Washington, Winona, Wright
EcoregionDriftless Area, Lake Agassiz Plain, North Central Hardwood Forests, Northern Glaciated Plains, Northern Lakes and Forests, Northern Minnesota Wetlands, Western Cornbelt Plains
Approximate Eco ProvinceEastern Broadleaf Forest, Laurentian Mixed Forest, Prairie Parkland, Tallgrass Aspen Parklands