Alnus viridis (Chaix) DC.
Betulaceae (Birch Family)
USDA Symbol: alvi5
In Alaska, Green Alder is a pioneer in disturbed areas, following landslides, logging, and glacial retreat. Adapted to soils too barren for other trees, this species improves soil conditions by adding organic matter and nitrogen from bacteria in its roots. Alder roots have clusters of nodules containing nitrogen-fixing bacteria, which convert atmospheric nitrogen into a form usable by plants. Alders therefore thrive on nutrient-poor sites, and when these shrubs die and decompose, they release stored nitrogen and enrich the soil for other plants. (Kershaw) It acts as a short-lived nurse tree for Sitka Spruce (Picea sitchensis), later dying when shaded by the larger conifer.
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Plant CharacteristicsDuration: Perennial
Leaf Retention: Deciduous
Leaf Arrangement: Alternate
Leaf Complexity: Simple
Leaf Venation: Pinnate
Breeding System: Flowers Unisexual , Monoecious
Fruit: Black, Brown
Size Class: 12-36 ft.
Bloom InformationBloom Color: Yellow , Green , Brown
Bloom Time: May , Jun
DistributionUSA: AK , CA , ID , MA , ME , MI , MN , MT , NC , NH , NY , OR , PA , TN , VT , WA , WI , WY
Canada: NB , NL , ON , PE
Native Distribution: SW. and central Alaska and Yukon southeast to NW. California and central Montana; in Alaska to alpine zone above timberline; in NW. California to 7000' (2134 m).
Native Habitat: Along streams and lakes and in valleys.
Growing ConditionsLight Requirement: Part Shade , Shade
Soil Moisture: Wet
Soil Description: Sandy
Conditions Comments: Alder roots have clusters of nodules containing nitrogen-fixing bacteria, which convert atmospheric nitrogen into a form usable by plants. Alders therefore thrive on nutrient-poor sites, and when these shrubs die and decompose, they release stored nitrogen.
BenefitUse Wildlife: Birds, Other Showy Insects
Find Seed or Plants
View propagation protocol from Native Plants Network.
National Wetland Indicator Status
From the National Organizations DirectoryAccording to the species list provided by Affiliate Organizations, this plant is on display at the following locations:
Natural Biodiversity - Johnstown, PA
Additional resourcesUSDA: Find Alnus viridis in USDA Plants
FNA: Find Alnus viridis in the Flora of North America (if available)
Google: Search Google for Alnus viridis
MetadataRecord Modified: 2018-01-12
Research By: TWC Staff