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

FOREST TREES OF THE PACIFIC SLOPE. 87
tinguishing this tree from its somewhat similar related species. The stems of
the cones are very stout, firm, and curved downward or inward toward the
branch. The open cone-scales are peculiarly stiff and resistant to pressure of
the hand; but are easily broken if squeezed together. The seed is a deep
chocolate brown. Seed-leaves, usually 6, about one-half inch long or shorter.
Wood usually a clear, very light yellow. The common color of this wood, also
of that of the white spruce and to some extent of the red spruce, with which it
may be mingled sometimes as lumber, is not an entirely safe character to rely
upon for identification. The color of wood from different individuals of the
same species often differs greatly, so that it is easy to confuse it with the
pale or yellowish white wood of the two other spruces. Black spruce wood is
mainly very fine-grained. Of the other eastern spruces it is the least important
commercially, mainly on account of its small size.
LONGEVITY.-Doubtless a moderately long-lived tree; average observed sizes
are from 125 to 200 years old. Stunted trees growing in very wet situations
and scarcely 2 inches in diameter are often from 50 to nearly 80 years old,
but appear to be thrifty, considering the unfavorable situation. Further records
of longevity are desirable.
RANGE.
Newfoundland to Hudson Bay and northwestward to Alaksa; southward in Michigan,
Wisconsin, Minnesota, and in the eastern mountains to North Carolina and Tennessee.
Northwestern range very Imperfectly known. It Is probably much the same as that
of white spruce, but further accurate field observations are required to establish the
coincidence of ranges. It seems likely that black spruce will prove to be far less
abundant in Alaska than the white spruce.
CANADA.-Abundant in Great Plains, especially north of Saskatchewan and on Beaver
and Athabaska rivers, extending westward to eastern slopes of Rockies and southward
to tributaries of Elbow River, 30 miles from Calgary. Northward, in Great Plains,
through Peace and Mackenzie river valleys, to within 20 miles of Arctic Ocean and
from mouth of Coppermine River (long. 116°) westward to Alaska. Crosses Continental
Divide into interior plateau of Rockies farther south than white spruce, being
common on high plateaus of Upper Fraser and Blackwater rivers (lat. 53°) and northward
on Stikine, Dease, Liard, Frances, and Pelly rivers. Abundant from Pelly River
to McQuestion River (tributary Stewart River) at about 3,500 feet elevation; at Dawson
and westward on Yukon River and southward on White River to a point 212 miles
from Its mouth.
ALASKA-There are no definite records for Yukon Valley, over which this tree very
probably extends, northward to south slopes of Endicott Range, westward to Bering
Sea, and southward to inland slopes of Pacific coast ranges. Records are available
for its occurrence on Cook Inlet, an arm of the Gulf of Alaska. Here it occurs
sparingly at about 2,000 feet elevation In swamps of the plateau on Kenai Peninsula,
especially on Chicaloon Flats, and in peat bogs at Hope, Sunrise, and Tyonek, on Cook
Inlet coast.
OCCURRENCE.
Essentially a swamp tree, characteristic of cold, wet bogs and margins of lakes; growvs
occasionally on high, well-drained hillsides, but is less abundant here than in wet sites,
and is small or stunted. Best growth in constantly moist, alluvial, well-drained soils, but
most abundant in wet soils. Depth of soil Is not essential, owing to shallow root system.
Grows on clay and heavy glacial drift, and sometimes even in sandy, hill soils, but of
poor growth in such soils.
In east, forms pure forests over limited and extensive areas, occurring also in mixed
stands. In northwest, best growth in limited or small areas of pure stand in moist,
well-drained alluvial bottoms of Athabaska River, and in river valleys in Saskatchewan
and north Manitoba. Valley of Yukon River, grows in wet localities, usually over buried
glaciers. Not common immediately on banks of the Yukon, but abundant in Pelly River
drainage on swampy parts of bottoms, on moss-covered north slopes, and at heads of
streams on low, broad divides. In mixture, associated with tamarack, black cottonwood,
balm-of-gilead, aspen, willows, and red alder.
CLIMATIC CONDITIoNS.-At north, climate extremely severe, with low atmospheric humidity,
small precipitation (sometimes not over 15 inches), great seasonal range of temperature,
and occasional strong, drying winds. Annual range of temperature, rarely less