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.
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.
Illustration Source: The Illustrated Flora of British Columbia
Present from Fall to Spring
Source: The USDA
||Value / Class
Moisture Regime (SMR)
[0 - very xeric; 4 - mesic;
8 - hydric]
of field plots
species was recorded in:
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)|
Source: Klinkenberg 2013
Synonyms and Alternate Names:
Alnus oregona Nutt.
Alnus oregona var. pinnatisecta Starker
1. Leaves finely once or twice saw-toothed; axillary buds unstalked, pointed; male catkins unstalked; stalks as long as or longer than the conelike sillicles..........................A. viridis
1. Leaves coarsely to irregularly round-toothed; axillary buds pedunculate, blunt or short-pointed; male catkins stalked; stalks shorter than the conelike silicles
2. Leaf margins rolled under; nutlets with narrow-winged margins.......................................A. rubra
2. Leaf margins not rolled under; nutlets wingless..................................A. incana
Source: Illustrated Flora of British Columbia, Volume 2
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.
This species flowers in the first week in March in the Fraser Delta.