Western Hemlock

(Tsuga heterophylla)

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Color Photograph: © by and courtesy of Charles Webber, California Academy of Sciences

Western Hemlock (Tsuga heterophylla)

Identifying Characters: The small, globular cones hanging downward from the ends of small branches and the flat, shiny green needles in two rows will separate this species from any other except Mountain Hemlock.

Similar Species: The cones of Western Hemlock and shorter (0.75 to 1 inch in length) and more globular than those of Mountain Hemock. The cones of Mountain Hemlock are 1 to 3 inches in length and distinctly cylindrical.

Measurements: Mature trees reach heights between 100 to 150 feet, but rare individuals exceed 200 feet. Diameter of older individuals at breast height is between 3 to 4 feet.

Cones: Cones 0.75 to 1 inch long, elliptical, and brown, hanging downward from the ends of the twigs.

Needles: Needles in two rows, 0.25 to 0.75 inches long; needles flat, flexible, rounded at the tip and not tapering at the apex; color shiny dark green above and with 2 white bands underneath.

Bark: Red-brown to gray brown, deeply into scaly ridges in older individuals.

Native Range: Western Hemlock is an important commercial tree species of the Pacific coast and northern Rocky Mountains. Along the Pacific coast, its range extends north along the Coast Ranges from central California to the Kenai Peninsula in Alaska, a distance of 3200 km (2,000 mi). It is the dominant species in British Columbia and Alaska along the Coast Mountains and on the coastal islands.

Inland it grows along the western and upper eastern slopes of the Cascade Range in Oregon and Washington and the west side of the Continental Divide of the northern Rocky Mountains in Montana and Idaho north to Prince George, British Columbia. (Silvics of North America. 1990. Agriculture Handbook 654.)

Habitat: Western Hemlock dominates on wet, acid soils. The species is most commonly found on flat areas or the lower slopes of mountains. The species is particularly common along the coastal regions of the Pacific Northwest.