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Search for native plants by scientific name, common name or family. If you are not sure what you are looking for, try the Combination Search or our Recommended Species lists.

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Alnus rhombifolia

Alnus rhombifolia Nutt.

White Alder

Betulaceae (Birch Family)

Synonym(s): Alnus rhombifolia var. bernardina

USDA Symbol: ALRH2

USDA Native Status: L48 (N)

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 fruit 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 Characteristics

Duration: Perennial
Habit: Tree
Leaf Retention: Deciduous
Leaf Arrangement: Alternate
Leaf Complexity: Simple
Leaf Venation: Pinnate
Leaf Margin: Serrate
Breeding System: Flowers Unisexual , Monoecious
Fruit Type: Samara
Size Notes: Height 40-50 feet, spread to 40 feet.
Leaf: Dark green and glossy above.
Fruit: Less than an inch long.

Bloom Information

Bloom Color: Green
Bloom Time: Sep , Oct , Nov

Distribution

USA: 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 Conditions

Water 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.

Benefit

Use 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

Propagation

Propagation 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

Region:AGCPAKAWCBEMPGPHIMWNCNEWMVE
Status: 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 on display at the following locations:

Santa Barbara Botanic Garden - Santa Barbara, CA
Native Seed Network - Corvallis, OR

Web Reference

Webref 37 - Calscape (2019) California Native Plant Society
Webref 38 - Flora of North America (2019) Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA.
Webref 23 - Southwest Environmental Information Network (2009) SEINet - Arizona Chapter

Additional resources

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

Metadata

Record Modified: 2023-03-09
Research By: TWC Staff

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