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

100 FOREST TREES OF THE PACIFIC SLOPE.
seed; they are borne nearly or quite at the ends of twigs. The male flowersscaly
bodies bearing pollen only-grow from the bases of leaves farther back
from the end of the twig. Most characteristic of the pendulous cones of these
trees are their 3-pointed scale-like bracts, which protrude conspicuously from
among the cone-scales (fig. 36). No other cones of native conifers, with persistent
scales, have protruding bracts. The cones mature in one season, soon
afterward falling from the trees. Two winged seeds are borne under each
cone-scale. Their small size and large, light wings permit the wind to distribute
them easily.
They are trees (mainly one species) of the greatest commercial importance,
and furnish the finest and largest saw timber of any native trees, if not of any
trees in the world. The slightly resinous, pine-like wood is most widely adapted
for construction. Two native species of these trees are known. One is distributed
more or less from the Rocky Mountain States to the Pacific coast,
while the other inhabits the mountains of southern California.
Douglas Fir; Douglas Spruce.
Pseudotstuga taxifolia a (toir.) Britt.
DISTINGUISHING CHARACTERISTICS.
Excepting the great sequoias of California, Douglas fir is the most gigantic
tree of the Pacific forests. Under the best conditions for growth it ordinarily
reaches 180 or 190 feet in height and from 34 to 6 feet in diameter. Trees over
200 feet high and 8 or 10 feet in diameter are to be found, but they are exceedingly
rare. Under less favorable conditions, such as prevail outside of the
humid Pacific coast region, it commonly attains a height of from 75 to 110
feet and a diameter of from 18 to 30 inches; while in high, exposed situations
it is greatly stunted, often under 5 feet in height. The typical crown form of X
young trees is a broad, sharp pyramid; the lower branches are straight or
drooping and the middle and higher ones trend upward, forming on the whole a
rather open head. All of the branches have numerous long, hanging side
branchlets, which are sometimes very long. In dense stands one-half or twothirds
of the lower branches are shaded out by the time the trees are 10 or 15
inches in diameter. Under these conditions the crowns of middle-aged and old
trees lose much of their pyramidal form, and become rounded or flattened.
The massive trunks, clear of branches for 80 or 100 feet (in the Pacific region),
are straight, and with only a slight taper. The ashy brown bark of young
trees, often chalky in patches, is thin, smooth, and but little broken, except near
the ground, until the trees are 12 to 14 inches in diameter. Later, and in old
trees, the bark becomes from 5 to 10 inches thick at the base of the trunk,
although higher up it remains much thinner. Sometimes very old trees have
bark from 18 to 24 inches thick. It is dark brown on the outside and clear redbrown
within. It is often very rough, with deep, wide furrows and great
ridges, which are connected at intervals by narrower cross ridges. There is
great variation in the character and markings of the bark in dry and humid
regions, and also in exposed and protected situations. Trees in exposed, dry
a Several authors maintain for this tree the name Pseudotsuga trumcroniata (Raf.)
Sudworth, which the writer has shown to be lawfully antedated by P. taxifolia (Poir.)
Britt- For a fill discussion of the basis of this deision.
1898.
ne ul 17 T)in.Fo. P . 2 91