De I. VNER VEW D Forest Trees of the Pacific Slope

70 FOREST TREES OF THE PACIFIC SLOPE.
long, narrow crowns with more or less weeping branches. Middle-aged and old
trunks have reddish cinnamon-brown bark, extremely thick (3 to 6 inches),
deeply furrowed near the base of the tree, where the ridges are strikingly
massive; 20 or more feet above, it is much thinner and less deeply furrowed.
The exceedingly thick bark of old and of half-grown trees is a most important
protection against fire. Very many large trees bear evidence of having passed
through a number of destructive forest fires without damage to their vitality.
The bark of young trees and branches is thin, scaly, and dark or grayish brown.
The color of the foliage, a pale yellowish green, becoming a bright lemon-yellow
in late fall, distinguishes the trees from their associates. The leaves, flatly
triangular and distinctly ridged or keeled on their inner face, are from about
1 inch to nearly 2 inches in length. In cross-section they show a single fibrovascular
bundle in the center and no resin ducts. The number of leaves in a
cluster, ranging from 14 to about 30, can not be depended upon as a distinctive
character. The cones (fig. 26) mature in one season and are ripe early in
August. They open soon afterwards and shed their seeds (fig. 26, a), which
are light chestnut brown. By the end of October or November the cones have
fallen from the trees. Cones vary from about 1 to 12 inches in length; their
foot-stalks are very short. Cone scales usually with a dense coating of delicate
whitish woolly hairs on the outside, below their centers. Seed-leaves, as a
rule, 6. Wood, clear reddish brown, heavy, and fine-grained; commercially
valuable. It is very durable in an unprotected state, differing greatly in this
respect from wood of the eastern larch.
LoNGEVITY.-Long-lived, attaining an age ordinarily of from 300 to 500 years,
while the largest trees are probably from 600 to 700 years old. Trees from 16
to 20 inches in diameter are from 250 to 300 years old. Further records of its
age limits are required.
RANGE.
High valleys and mountain slopes of southeastern British Columbia, northwestern
Montana, northern Idaho, Washington, and southward to Oregon.
WASHINGTON.-Mountains of northeastern part, Blue Mountains, and southern part on
east side of Cascades. Not detected north of Omak Creek (eastern tributary Okanogan
River in north central Oregon, latitude 480 16'), nor in Cascades north of head of
Peshastin Creek (tributary Wenache River, latitude 470 30'). Mount Rainier National
Forest, 2,200 to 5,600 feet on divide between Natches and American rivers: also on upper
Natches, Tieton, upper Yakima, Atanonm, Klickitat, and White Salmon watersheds, and
on Mount Adams. Colville National Forest, northward from Columbia River to 4,000
feet in Kettle Range. General in Washington addition to Priest River National Forest;
Columbia River in latitude 46° to 49', and on Kamiak Butte, near Pullman (eastern
part State). Occasional stands in Blue Mountains of Wenaha National Forest, at 2,700
to 6,000 feet.
OREGON.-Blue and Wallowa mountains, and Cascades southward to head of Squaw
Creek (T. 16 S., R. 9 E., lat. 440 8'). Cascades, mainly on east side, but extending
across divide for short distance, along west side, from township 4, south (south of
Mount Hood) to head of Clackamas River (T. 6 S.). On north (at 2,000 feet to 4,600
feet), east, and south sides of Mount Hood and southward, on east side of Cascades, to
Tamarack Mountain (T. 6 S., R. 9 E.) ; here very abundant. Found next on Metolius
River (T. 12 S., R. 9 E.), southeast sides of Mount Jefferson, thence extending
southward to head of Squaw Creek (T. 16 S., R. 9 E.), the southmost limit now
known. In Blue Mountains, on both sides of north and south ranges (included in eastern
divieion of Blue Mountains National Forest), at 5,000 to 6,000 feet; southward to head
of John Day River, and westward to township 30 east. Eastward through Wallowa
Mountains to Big and Little Sheep Creeks (T. 46 and 47 E., R. 3 and 4 S.) nearly to the
Idaho line.
The detailed range of western larch in Montana and Idaho will be dealt with
In a later bulletin.
OCCURRENCE.
Mountain slopes, preferring north and west exposures-stream bottoms, valleys, and
flats ; rare to canyon bottoms and on mountain summits Exacting in requirements