Alnus rhombifolia Nutt.
Betulaceae (Birch Family)
Synonym(s): Alnus rhombifolia var. bernardina
USDA Symbol: alrh2
Medium-sized to large tree with tall, straight trunk and open, rounded crown; showy in winter with long, golden-colored male catkins hanging from slender, leafless twigs. In cultivation, this is a 10-30 ft. tree with a tall, straight trunk and ascending or spreading branches pendulous at the ends. The bark is white to grayish and broken into plates on old trunks. The dark-green, deciduous leaves are glossy, oval and doubly toothed. Catkins are 2-several per cluster, and cones are less than 1/2 in. long. White Alder, named for its pale green foliage, is the only alder native in southern California. Limited to permanent streams, it is a good indicator of water.
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Plant CharacteristicsDuration: Perennial
Leaf Retention: Deciduous
Leaf Arrangement: Alternate
Leaf Complexity: Simple
Leaf Venation: Pinnate
Leaf Margin: Serrate
Breeding System: Flowers Unisexual , Monoecious
Size Notes: Height 40-50 feet, spread to 40 feet.
Leaf: Dark green and glossy above.
Fruit: Cones less than an inch long.
Size Class: 36-72 ft.
Bloom InformationBloom Color: Green
Bloom Time: Sep , Oct , Nov
DistributionUSA: CA , ID , MT , NV , OR , WA
Native Distribution: Most of cismontane CA, n., on the e. side of the Cascades, to B.C. & c. ID
Native Habitat: Stream banks; mostly below 5000 ft.
Growing ConditionsWater Use: High
Light Requirement: Part Shade
Soil Moisture: Wet
CaCO3 Tolerance: None
Soil Description: Moist to wet soils.
Conditions Comments: Fast-growing. Alders fix nitrogen and thus serve as nutrient-giving pioneers in reclamation projects.
BenefitUse Ornamental: Sometimes planted as an ornamental in wet sites.
Use Food: Bark used for tea.
Use Medicinal: Leaves used for fleas, burns, eyewash.
Use Other: Shoots used for arrows, roots for baskets. Bark used to make red dye.
Interesting Foliage: yes
PropagationPropagation Material: Seeds , Softwood Cuttings
Description: Propagated from freshly collected seeds released from the female conelets in fall.
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
Find seed sources for this species at the Native Seed 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:
Santa Barbara Botanic Garden - Santa Barbara, CA
Native Seed Network - Corvallis, OR
BibliographyBibref 698 - Native Plants for Use in the California Landscape (1978) Labadie, E. L.
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Additional resourcesUSDA: Find Alnus rhombifolia in USDA Plants
FNA: Find Alnus rhombifolia in the Flora of North America (if available)
Google: Search Google for Alnus rhombifolia
MetadataRecord Modified: 2007-01-01
Research By: TWC Staff