Tsuga heterophylla
Tsuga canadensis
pruche de l'ouest, western hemlock
Canada hemlock, eastern hemlock, hemlock spruce, pruche du Canada
gray-brown, scaly and moderately fissured.
brownish, scaly and fissured.
yellow-brown, finely pubescent.
yellow-brown, densely pubescent.
ovoid, gray-brown, 2.5–3.5mm.
ovoid, 1.5–2.5mm.
(5–)10–20(–30)mm, mostly appearing 2-ranked, flattened;
abaxial surface glaucous with 2 broad, conspicuous stomatal bands, adaxial surface shiny green (yellow-green);
margins minutely dentate.
(5–)15–20(–25)mm, mostly appearing 2-ranked, flattened;
abaxial surface glaucous, with 2 broad, conspicuous stomatal bands, adaxial surface shiny green (yellow-green);
margins minutely dentate, especially toward apex.
cones ovoid, (1–)1.5–2.5(–3) × 1–2.5cm;
scales ovate, 8–15 × 6–10mm, apex round to pointed.
cones ovoid, 1.5–2.5 × 1–1.5cm;
scales ovate to cuneate, 8–12 × 7–10mm, apex ± round, often projected outward.
=24.
=24.
Tsuga heterophylla
Tsuga canadensis
Tsuga heterophylla is a dominant species over much of its broad distributional range. It has become the most important timber hemlock in North America. The wood is superior to that of other hemlocks for building purposes and it makes excellent pulp for paper production.
Tsuga × jeffreyi (Henry) Henry was described from southwestern British Columbia and western Washington as a hybrid between T. heterophylla and T. mertensiana. Hybridization is rare, if it occurs at all, and it is therefore of little consequence (R.J. Taylor 1972). At the upper elevational limits of its distribution and under stressful conditions, T. heterophylla tends to resemble T. mertensiana, e.g., leaves are less strictly 2-ranked and stomatal bands on the abaxial leaf surfaces are less conspicuous than at lower elevations.
Western hemlock (Tsuga heterophylla) is the state tree of Washington.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Numerous cultivars of Tsuga canadensis have been developed, including compact shrubs, dwarfs, and graceful trees. Wood of the species tends to be brittle and inferior to that of the other North American hemlocks.
Eastern hemlock (Tsuga canadensis) is the state tree of Pennsylvania.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
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BC, 
CA, 
OR, 
WA - Local Web sites: CalFlora, CalPhotos,
Flora NW, 
PNW Herbaria 
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