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

Alnus alnobetula subsp. sinuata
Sitka alder
Betulaceae (Birch family)

Introduction to Vascular Plants

© Adolf Ceska  Email the photographer   (Photo ID #13419)

E-Flora BC Static Map
Distribution of Alnus alnobetula subsp. sinuata
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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.
Three subspecies occur in BC.

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 alnobetula ssp. sinuata

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 1172 2500
Slope Gradient (%) 0 22 205
Aspect (degrees)
[0 - N; 90 - E; 180 - S; 270 - W]
0 27 360
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: AT(2), BG(4), BWBS(238), CMA(1), CWH(92), ESSF(802), ICH(648), IDF(186), MH(26), MS(580), PP(7), SBPS(16), SBS(575), SWB(2)

Synonyms and Alternate Names

Alnus crispa subsp. laciniata Hultén
Alnus crispa subsp. sinuata (Regel) Hultén
Alnus crispa var. sinuata
Alnus sinuata (Regel) Rydb.
Alnus viridis (Chaix) DC.
Alnus viridis var. sinuata Regel
Duschekia sinuata (Regel) Pouzar

Taxonomic and Nomenclatural Links

Additional Photo Sources

General References