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

Kalmia microphylla subsp. occidentalis (Hook.) A. Heller
western bog-laurel (alpine laurel; swamp laurel)
Ericaceae (Crowberry family)

Introduction to Vascular Plants

© Brian Klinkenberg  Email the photographer   (Photo ID #274)

E-Flora BC Static Map
Distribution of Kalmia microphylla
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Species Information

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Low shrub; stems 10-50 cm tall, much branched; young stems finely hairy but soon becoming glabrous.
Evergreen, opposite, leathery, oblong-lanceolate to narrowly oblong, (0.6) 0.8-4 cm long, (2) 3-11 mm wide, entire, margins often rolled under, shiny, dark green and glabrous above, greyish and very finely and densely short glandular-hairy beneath, often with a prominent midrib; stalks 2-5 mm long.
In terminal 1- to 12-flowered clusters; flower stalks 1-4 cm long, usually glabrous; corollas deep pinkish-rose, saucer-shaped, 1-2 cm wide; calyces deeply 5-lobed, lobes egg-shaped, 2-3 mm long, glabrous or occasionally sparsely and minutely fringed; stamens 10, held in sacs on petals until full bloom, densely hairy just above the base, otherwise glabrous.
Five-valved capsules, nearly globe-shaped, glabrous, about 4 mm wide and 5 mm long.
Two subspecies are recognized in BC:

1. Leaves oval to broadly elliptic, usually less than 2 cm long, and less than 2 times as long as wide; calyces less than 7 mm wide; plants occurring E of the Coast-Cascades Range in BC and usually at high elevations..............ssp. microphylla

1. Leaves lance-shaped, usually 2.5 cm long or longer, and 2.5-4 times as long as wide; calyces more than 7 mm wide; plants of coastal BC and intermittently inland, usuallyat low to moderate elevations..................ssp. occidentalis (Small) Taylor & MacBryde

Source: The Illustrated Flora of British Columbia

USDA Species Characteristics

Flower Colour:
Blooming Period:
Late Spring
Fruit/Seed characteristics:
Colour: Brown
Present over the Summer
Source:  The USDA

Habitat / Range

Peat bogs, wet peaty forests and meadows from the lowland through alpine zones; frequent throughout BC; N to AK, YT and NT, E to NW MB, and S to C CA, NV, UT, and CO.

Source: The Illustrated Flora of British Columbia


Ecological Framework for Kalmia microphylla

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) 6 1040 2400
Slope Gradient (%) 0 6 100
Aspect (degrees)
[0 - N; 90 - E; 180 - S; 270 - W]
0 5 360
Soil Moisture Regime (SMR)
[0 - very xeric; 4 - mesic;
8 - hydric]
0 6 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(9), BAFA(7), BWBS(4), CDF(5), CMA(2), CWH(304), ESSF(266), ICH(78), IDF(4), IMA(4), MH(60), MS(19), SBPS(2), SBS(84), SWB(3)


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.

Synonyms and Alternate Names

Kalmia microphylla subsp. occidentalis (Small) Roy L. Taylor & MacBryde
Kalmia microphylla var. occidentalis (Small) Ebinger
Kalmia occidentalis Small
Kalmia polifolia Wangenh.
Kalmia polifolia subsp. microphylla (Hook.) Calder & Roy L. Taylor
Kalmia polifolia subsp. occidentalis (Small) Abrams
Kalmia polifolia var. microphylla (Hook.) Rehder

Taxonomic and Nomenclatural Links

Additional Photo Sources

General References