E-Flora BC: Electronic Atlas of the Flora of British Columbia

Alnus viridis (Chaix) DC.
green alder (green alder (ssp. crispa); Sitka alder (ssp. sinuata))
Betulaceae (Birch family)

Introduction to Vascular Plants

© Bryan Kelly-McArthur  Email the photographer   (Photo ID #87754)

E-Flora BC Static Map
Distribution of Alnus viridis
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Alnus viridis ssp. crispa

Species Information

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Deciduous shrub or tree, 1-5 m tall; pointed axillary buds without stalks; bark scaly, sometimes lichen-covered, yellowish-brown or grey.
Alternate, deciduous, smooth, finely toothed 1-2 times, oval with pointed tips, 4-10 cm long, brownish in the fall.
Inflorescence of male and female catkins which open at the same time as the leaves on current year's growth; male catkins unstalked.
Small nutlets, with broad wings; female cones 1.5-2 cm long, egg-shaped.
Two subspecies occur in BC:

1. Leaf margins shallowly lobed as well as finely saw-toothed..................... ssp. sinuata (Regel) A.& D. Love

1. Leaf margins not at all or only slightly lobed, mostly merely finely saw-toothed..................... ssp. crispa [Ait.] Turrill

Source: The Illustrated Flora of British Columbia

Habitat / Range

Moist slopes, streambanks, avalanche tracks, bogs and fens in all zones; ssp. crispa frequent in N BC, ssp. sinuata common throughout S BC, becoming less frequent and transitional to ssp. crispa in N BC; circumboreal, E to PQ and S to NC, MN, CO and CA.

Source: The Illustrated Flora of British Columbia


Ecological Framework for Alnus viridis

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) 0 1031 2750
Slope Gradient (%) 0 22 130
Aspect (degrees)
[0 - N; 90 - E; 180 - S; 270 - W]
0 351 360
Soil Moisture Regime (SMR)
[0 - very xeric; 4 - mesic;
8 - hydric]
0 4 8
Modal Nutrient Regime
Number of field plots
 species was recorded in:
Modal BEC Zone Class
All BEC Zones (# of stations/zone) species was recorded in: BWBS(337), CMA(1), CWH(193), ESSF(545), ICH(481), IDF(95), MH(43), MS(179), PP(2), SBPS(49), SBS(589), SWB(18)


The climate type for this species, as reported in the: "British Columbia plant species codes and selected attributes. Version 6 Database" (Meidinger et al. 2008), is not evaluated, unknown or variable.

Taxonomic and Nomenclatural Links

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General References