Lady Bird Johnson Wildflower Center - The University of Texas at Austin information

 Native Plant Database

Alnus incana

Gray alder, Speckled alder

Betulaceae (Birch Family)

Alnus incana (Gray alder)
Smith, R.W.
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.

Image Gallery:

1 photo(s) available

Plant Characteristics

Duration: Perennial
Habit: Shrub , Tree
Leaf Retention: Deciduous
Leaf Arrangement: Alternate
Leaf Complexity: Simple
Leaf Shape: Elliptic , Ovate
Leaf Venation: Pinnate
Leaf Margin: Double-serrate
Leaf Apex: Acuminate , Acute , Obtuse
Leaf Base: Cuneate , Rounded
Breeding System: Flowers Unisexual , Monoecious
Size Notes: Height to 25 M.
Leaf: Green
Size Class: 12-36 ft.

Bloom Information

Bloom Time: Mar , Apr , May


USA: AK , AZ , CA , CO , CT , ID , IL , IN , IA , ME , MD , MA , MI , MN , MT , NV , NH , NJ , NM , NY , ND , OH , OR , PA , RI , UT , VT , VA , WA , WV , WI , WY
Canada: AB , BC , MB , NB , NL , NS , ON , PE , QC , SK
Native Distribution: Lab. to AK, s. to NJ, mts. of WV, n.e. IL, n.e. IA, MN, n.e. ND & w. mts. to NM & c. CA
Native Habitat: Wetlands & stream edges

Growing Conditions

Water Use: High
Light Requirement: Sun , Part Shade , Shade
Soil Moisture: Wet , Moist
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.


Use 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

Last Update: 2012-06-30