Tsuga mertensiana (Bong.) Carrière
mountain hemlock
Pinaceae (Pine family)

Introduction to Vascular Plants


© Dave Ingram     (Photo ID #26824)


E-Flora BC Static Map

Distribution of Tsuga mertensiana
Click here to view the full interactive map and legend


This is an evergreen coniferous tree species that is common in western BC at high elevations.

Species Information

Tree, seldom to 40 m tall, much shorter near tree-line; narrow crown, with slightly drooping leader (growing tip), less evident with age; twigs strongly hairy with mix of short and long hairs; bark thick, strongly furrowed and ridged, dark purplish- to reddish-brown.
Needles thickened in centre and somewhat 4-sided, round to blunt at tip, (10) 12-20 mm long, spread around branches to somewhat upturned, not forming flat sprays; yellow-green to deep blue-green, stomata on both surfaces, rarely whitish.
Seed cones maturing from green or purple to dark brown, (2.5) 3-6 (7) cm long, cylindric with narrowed ends; pollen cones bluish, 3-4 mm long.
See above for hybridization with T. heterophylla.

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 Summer
Fruit/Seed characteristics:
Colour: Brown
Present from Summer to Fall
Source:  The USDA


Ecological Framework for Tsuga mertensiana

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)
980 5 2500
Slope Gradient (%)
29 0 130

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

241 0 360
Soil Moisture Regime (SMR)
[0 - very xeric; 4 - mesic;
8 - hydric]
4 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

AT(3), CMA(17), CWH(675), ESSF(427), ICH(60), IDF(4), MH(737), MS(15), SBS(3), SWB(1)

Habitat and Range

Wet to dry slopes in the lowland to subalpine zones; common at high elevations along W BC and infrequent in SE BC and lower elevations of NW BC coast; N to SE AK and S to C CA, N ID and W MT.

SourceThe Illustrated Flora of British Columbia