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

FOREST TREES OF THE PACIFIC SLOPE.
Endures most shade with favorable moisture, soil, and climatic conditions. Growth and
size is checked ordinarily in proportion to intensity of shade endured.
REPRoDUcTION.-Prolific seeder under favorable conditions, every 2 to 3 years or more;
some seed borne locally every year. Bulk of seed from thrifty, mature trees In full sunlight.
In exposed places, even small scrubby trees bear seed. Seed has fairly high rate
of germination, and persistent vitality. Moist vegetable mold best seed-bed, but germiration
and growth of seedlings good on moist mineral soil. Partial shade favorable to
early seedling stages. Reproduction good under old trees and In open, but especially
good in openings and under thinned stands, where the dense thickets frequently exclude
other more valuable trees. In cool, moist places, however, white fir often enters such
thickets and predominates. Frequently the first of conifers In chaparral and oak growth
at lower edge of timber belt, proving its great adaptation to different degrees of light,
moisture, and soil, and its general hardihood in seedling stages.
THUSA. ARBORVIT2ES.
The arborvittes are commonly known as cedars. They are medium to very
large sized evergreen trees. The foliage consists of minute, overlapping, scalelike
leaves, arranged as in Libocedrus, and conspicuously flat, on short side
branchlets, and the branchlets are arranged in one plane, forming a flat spray.
Seedling leaves are narrowly lance-shaped and sharp-pointed, and spread widely
from the stem. The very light wood has an exceedingly characteristic aromatic
odor. Male and female flowers are borne on the same tree, usually on different
twigs. They are minute and inconspicuous, especially the female flowers. As
a rule, they open in early spring. The small solitary cones (figs. 59 and 60)
mature in one season, shedding their minute, very narrowly winged seeds in
early autumn. The cones, strongly bent back upon the branchlets, are light
russet-brown, and composed of about 8 thin scales, arranged in pairs, each pair
alternating at right angles with the preceding one, as in the arrangement of
the leaves. The two or three middle pairs, which are larger than the others,
bear 2 seeds under each scale. The thin, gauzy seed-wings (on two sides of the
seed, and always lighter colored than the body of the seeds) are very buoyant,
so that they may be carried by the wind for a considerable distance from the
parent trees. Minute resin-cells in the seed-coats give the seed a strong aromatic
odor.
Wood exceedingly valuable for timber. Particularly famed for its durability
under all kinds of exposure, and especially useful in ground and water construction
where great strength is not required.
Two species are indigenous to the United States and Canada. One, a small
or medium-sized tree, inhabits the northeastern States and adjacent Canadian
Provinces, while the other, a very large tree, grows in the northwestern States,
where it extends far northward in the coast region.
Western Red Cedar; Red Cedar.
Thuja plicata Don.
DISTINGUISHING CHARACTER1STICS.
The lumbermen's and woodsmen's name for this tree is " red cedar," or
simply "cedar." The former name, while fairly applicable to the dull, slightly
reddish brown wood, is unfortunate in view of the fact that two or three
widely known eastern junipers with really red wood are most persistently called
" red cedar," and probably always will be, for they were known nearly a century
before this western cedar was discovered.
The most prominent characteristic of western red cedar is its decidedly
eonical trunk form. Very old trees are enormously " swell-butted " and are conspicuously
in-folded or fluted at the base and for from 10 to 20 feet above it.
153