Alnus rubra Bong.
red alder
Betulaceae (Birch family)

Introduction to Vascular Plants


© Brian Klinkenberg     (Photo ID #3768)


E-Flora BC Static Map

Distribution of Alnus rubra
Click here to view the full interactive map and legend

Species Information

Deciduous shrub or tree, up to 25 m tall; axillary buds with stalks; bark scaly, often lichen-covered, yellowish-brown or grey-splotched with white.
Alternate, deciduous, smooth, coarsely to irregularly toothed, the teeth pointing outwards, leaf margins rolled under, brownish in the fall.
Inflorescence of male and female catkins which open before the leaves enlarge; male catkins with stalks.
Small nutlets, with narrow-winged margins; female cones 1.5-2.5 cm long, egg-shaped.

SourceThe Illustrated Flora of British Columbia


If more than one illustration is available for a species (e.g., separate illustrations were provided for two subspecies) then links to the separate images will be provided below. Note that individual subspecies or varietal illustrations are not always available.

USDA Species Characteristics

Flower Colour:
Blooming Period:
Early Spring
Fruit/Seed characteristics:
Colour: Brown
Present from Fall to Spring
Source:  The USDA


Ecological Framework for Alnus rubra

The table below shows the species-specific information calculated from
original data (BEC database) provided by the BC Ministry of Forests and Range.
(Updated August, 2013)

Site Information
Value / Class




Elevation (metres)
128 0 1700
Slope Gradient (%)
12 0 150

Aspect (degrees)
[0 - N; 90 - E; 180 - S; 270 - W]

167 0 360
Soil Moisture Regime (SMR)
[0 - very xeric; 4 - mesic;
8 - hydric]
5 0 8
Modal Nutrient Regime
# of field plots
 species was recorded in:
Modal BEC Zone Class

All BEC Zones (# of stations/zone) species was recorded in

BWBS(1), CDF(151), CWH(1265), ICH(9), IDF(7), MH(4), SBS(1), SWB(1)

Habitat and Range

Moist woodlands, forests, floodplains and clearcuts in the lowland and montane zones; common in coastal BC; N to SE AK and S to CA.

SourceThe Illustrated Flora of British Columbia


Synonyms and Alternate Names:
Alnus oregona Nutt.
Alnus oregona var. pinnatisecta Starker

Taxonomic Notes

Cut-leaf Red Alder

Red alder is probably the most common deciduous tree in the southern part of British Columbia. The leaves normally have shallow, rounded teeth along their margins. The leaves of the cut-leaf mutant form have irregular, sharply pointed teeth and lobes, thus resembling some black oak leaves more than alder leaves.

Source: Extracted with permission from Griffiths and Ganders, 1983.

Flowering Period

This species flowers in the first week in March in the Fraser Delta.


Griffiths, Anthony J. F. and Fred R. Ganders. 1983. Wildflower Genetics: A Field Guide for British Columbia and the Pacific Northwest. Flight Press, Vancouver.