[Hemlocks: The Genus Tsuga in Mt. Adams Country]

Black Hemlock, Mountain Hemlock

Tsuga mertensiana

Synonyms: Abies hookeriana, Abies mertensiana, Hesperopeuce mertensiana, Picea hookeriana, Tsuga crassifolia, Tsuga mertensiana ssp. mertensiana

Black Hemlock, Mountain Hemlock: Tsuga mertensiana (Synonyms: Abies hookeriana, Abies mertensiana, Hesperopeuce mertensiana, Picea hookeriana, Tsuga crassifolia, Tsuga mertensiana ssp. mertensiana)

The photo above shows the tip of a typical branch of mountain hemlock. The needles of this species are arranged around all sides of the branches and are somewhat thickened in cross-section and measure from 1-2 cm long. The cones are roughly elliptical in shape and measure from 3-7 cm long. The similar western hemlock has needles which are more 2-ranked on the sides of the twigs with the needles of unequal length. The cones of the western hemlock are roughly egg-shaped and measure from 1.5-2.5 cm long. Photographed at treeline at Crystal Lake on the western slopes of Mt. Adams........September 25, 2005.

Black Hemlock, Mountain Hemlock: Tsuga mertensiana (Synonyms: Abies hookeriana, Abies mertensiana, Hesperopeuce mertensiana, Picea hookeriana, Tsuga crassifolia, Tsuga mertensiana ssp. mertensiana)

A large mountain hemlock which survived the Cascade Creek Fire. This plant is located several hundred feet in elevation below the junction of the South Climb Trail and Round the Mountain Trail #9, Mount Adams Wilderness...........October 23, 2013.

Black Hemlock, Mountain Hemlock: Tsuga mertensiana (Synonyms: Abies hookeriana, Abies mertensiana, Hesperopeuce mertensiana, Picea hookeriana, Tsuga crassifolia, Tsuga mertensiana ssp. mertensiana) - Upper cone-bearing portion of a Black Hemlock, Mountain Hemlock: Tsuga mertensiana (Synonyms: Abies hookeriana, Abies mertensiana, Hesperopeuce mertensiana, Picea hookeriana, Tsuga crassifolia, Tsuga mertensiana ssp. mertensiana)

The upper portion of mountain hemlock as seen at left near treeline along the Round the Mt. Trail #9 at the Aiken Lava Flow on the southern slopes of Mt. Adams........October 22, 2005. Notice how the tip of the tree arches to the side, a diagnostic identification feature for this genus. This species may be found from about 4000' up to treeline. The photo at right shows the upper half of a mountain hemlock which is loaded with maturing but still green cones. Observed along the Round the Mountain Trail #9 west of Crooked Creek, Yakama Nation lands at Bird Creek Meadows, Mount Adams.....September 4, 2022.

Cones of Black Hemlock, Mountain Hemlock: Tsuga mertensiana (Synonyms: Abies hookeriana, Abies mertensiana, Hesperopeuce mertensiana, Picea hookeriana, Tsuga crassifolia, Tsuga mertensiana ssp. mertensiana)

The photo above shows an unopened and open cone of mountain hemlock as seen near treeline along the Round the Mt. Trail #9 at the Aiken Lava Flow on the southern slopes of Mt. Adams.......October 22, 2005. The cones of mountain hemlock measure from 2.5-7 cm long, while those of the western hemlock measure from 1.5-2.5 cm long.

Black Hemlock, Mountain Hemlock: Tsuga mertensiana (Synonyms: Abies hookeriana, Abies mertensiana, Hesperopeuce mertensiana, Picea hookeriana, Tsuga crassifolia, Tsuga mertensiana ssp. mertensiana)


Black Hemlock, Mountain Hemlock: Tsuga mertensiana (Synonyms: Abies hookeriana, Abies mertensiana, Hesperopeuce mertensiana, Picea hookeriana, Tsuga crassifolia, Tsuga mertensiana ssp. mertensiana) - Black Hemlock, Mountain Hemlock: Tsuga mertensiana (Synonyms: Abies hookeriana, Abies mertensiana, Hesperopeuce mertensiana, Picea hookeriana, Tsuga crassifolia, Tsuga mertensiana ssp. mertensiana)

The photo above left shows a krummholtz mountain hemlock as seen along the South Climb Trail (below the toe of the Crescent Glacier) on the southern slopes of Mt. Adams........August 23, 2008. A conifer in such alpine conditions can grow to a normal width on those parts of the plant protected by a sufficient depth of snow during the winter. The upper part of the plant that extends beyond the protective blanket of snow is exposed to harsh, cold and drying winds and so grows at a much slower rate and thus is much reduced in size. The photo at right shows a similar mountain hemlock at the terminal moraine for the Adams Glacier in the vicinity of the head of the Lewis River, Mount Adams Wilderness.......August 27, 2016.

Black Hemlock, Mountain Hemlock: Tsuga mertensiana (Synonyms: Abies hookeriana, Abies mertensiana, Hesperopeuce mertensiana, Picea hookeriana, Tsuga crassifolia, Tsuga mertensiana ssp. mertensiana) - Krummholtz Black Hemlock, Mountain Hemlock: Tsuga mertensiana (Synonyms: Abies hookeriana, Abies mertensiana, Hesperopeuce mertensiana, Picea hookeriana, Tsuga crassifolia, Tsuga mertensiana ssp. mertensiana)

A young mountain hemlock seen at left growing above 8000' in a boulder field on the terminal moraine of the Adams Glacier above High Camp, Mount Adams Wilderness...........August 19, 2013. The photo at right shows a krummolz, alpine form of mountain hemlock seen at the southern base of the moraine for the Mazama Glacier, Yakama Nation lands at Bird Creek Meadows, Mount Adams......September 14, 2022.

Paul Slichter