Tsuga mertensiana
(Mountain Hemlock)

Class: Pinopsida
Order: Pinatae
Family: Pinaceae
Family Description: Pine
Key Characteristics:
Also known as Black Hemlock.
  • needles slightly bulged in the mid-length , thus slightly 4-sided, stomata equal on both upper and lower surfaces, varying in color from yellow-green-to dark bluish-green, may be up turned or point in all directions equally around the twig, mostly 12-20 mm long, slightly pointed or round-tipped.
  • staminate cones small, 3-4 mm long, bluish;
  • ovulate cones, purplish to brownish-purple, somewhat pointed on each end of cylindric shape, commonly 3-6 cm long.
  • dark brown, about 4 mm long plus wing which is 5-6 mm long;
  • cotyledons commonly 3-5.

General Description:
A sharp pointed, pyramidal tree, from a few m tall on bleak mt. ridges to 45 m tall at lower elevations under favorable conditions; trunk 5-12 dm in diameter, with thick bark divided into rounded ridges; leaves mostly spreading from all sides of the branches, curved, 15-20 mm long, with stomata on both surfaces; cones oblong-cylindric, yellowish to purplish; scales wedge-shaped; seeds about 3 mm long, with long wings. Mts. W. Mont. to Alaska, across N. Idaho and to Calif.

At elevations of 4000-7000 feet elevation from southern Alaska and western British Columbia to northern California Sierra Nevada mountains to west central Nevada, east to southeastern British Columbia to northern Idaho, northeastern Oregon and western Montana, in Washington in both the Cascade and Olympic Mountains.

Commonly found on subalpine to alpine exposed ridges and slopes along the coast line from southeastern Alaska into Washington and in scattered locations inland in British Columbia, Idaho and Montana, Oregon and Northern California. Mountain Hemlock seems to prefer sheltered, areas with deep, well-drained, but moist soils where the precipitation is high and winters cold. Associate species are Sitka Spruce, Western Hemlock, Subalpine Fir, Red Fir and Lodgepole pine or may occur in almost pure stands.

The light weight wood is mostly used only when other wood is not available for rough construction. Wildlife value seems limited, but cover is utilized by blue grouse and Douglas Chickarees east the bark, buds and seeds.

Important State References:
No information available at this time
Photos & information written by Dr. Karl E. Holte,© 2002