western hemlock
Pinaceae (Pine family)
Introduction to Vascular Plants
Introduction
This is a tall evergreen coniferous tree species that is common in south-eastern and western BC.
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Species Information
General:
Tree to 50 (60) m tall; narrow crown, with noticeably drooping leader (growing tip); young twigs covered with mix of short hairs and longer hairs; bark rough and scaly, strongly furrowed and ridged in older trees, dark brown to reddish-brown.
Leaves:
Needles somewhat flattened, rounded at tip, 8-20 (25) mm long and characteristically unequal in length, spread unevenly at right angles to the branches to form feathery, flat sprays; glossy and yellow-green on upper surface, almost entirely white-stomatiferous on the lower.
Cones:
Seed cones maturing from green to brown, 1.5-2.5 cm long, oblong-egg-shaped; pollen cones yellow, 3-4 mm long.
Notes:
Hybrids with T. mertensiana have been reported (T. x jeffreyi [Henry] Henry) but are considered rare; some reports may be at upper elevations of its range where T. heterophylla may take on some characteristics of T. mertensiana, e.g., leaves less 2-ranked and stomatal bands on the lower leaf surfaces less distinct.
Illustration
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
USDA Species Characteristics
Blooming Period:
Mid Spring
Fruit/Seed characteristics:
Colour: Brown
Present from Summer to Fall
Source: The USDA
Ecology
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 |
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|
Avg |
Min |
Max |
|
| Elevation
(metres) |
651 | 0 | 2750 |
| Slope
Gradient (%) |
26 | 0 | 410 |
|
Aspect (degrees) |
273 | 0 | 360 |
| Soil
Moisture Regime (SMR) [0 - very xeric; 4 - mesic; 8 - hydric] |
4 | 0 | 8 |
| Modal
Nutrient Regime
Class |
C | ||
| #
of field plots species was recorded in: |
11893 | ||
| Modal
BEC Zone Class |
CWH | ||
|
All BEC Zones (# of stations/zone) species was recorded in |
CDF(71), CMA(1), CWH(5619), ESSF(920), ICH(4231), IDF(104), MH(373), MS(75), SBS(128) | ||
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Source:
Klinkenberg 2013
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Habitat and Range
Moist to dry slopes, river terraces and flats in the lowland and montane zones; common in and W of the Coast-Cascade Mountains in W BC and in SE BC; N to SE AK and S to N CA, N ID and NW MT.Status Information
Taxonomic Keys
1. Needles flattened in cross section, grooved and greenish on upper surface, with two white (stomatiferous) bands below, tending to form flat spray-like branches; cones egg-shaped, 1.5-2.5 cm long......................Tsuga heterophylla
1. Needles nearly semi-circular in cross section (flat on top), bluish-green on both surfaces, not forming flat spray-like branches, but spreading in all directions; cones cylindric, narrowed at each end, 3.7 cm long........................Tsuga mertensiana Source: the Illustrated Flora of British Columbia |