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.
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.
-
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.
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.
-
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.
-
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