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

20 FOREST TREES OF THE PACIFIC SLOPE.
fall when a set of new leaves is being formed at the ends of the branches.
The fruits of pines are woody, scaly cones, matured in from two to three years.
The cones of some pines remain on the trees only a few weeks after ripening,
while those of others persist for many years, or even are so firmly attached as
to be entirely enveloped by the annual diameter growth of the tree. At mnaturity
most pine cones open under the heat of the sun and liberate their seeds;
a few pines, however, rarely open their cones except under the heat of a forest
fire. This fact explains how certain pines often reproduce themselves after
the original forest has been killed by fire, since not all of the cones are burned
enough to destroy their seeds, and the seeds are scattered after the fire. The
flowers of the pines are of two sexes, male and female, borne usually on different
branches of the same tree. Male flowers, which produce pollen, are short,
oval, and bud-like, or long cylindrical bodies, clustered at-the ends of mature
leafy branches. They are bright red, yellow, or orange. The female flowers,
which produce cones and seed, are small, greenish, scaly, cone-like bodies, produced
singly or in pairs or groups near the ends of young growing shoots of
the spring. After fertilization of the two ovules (under each scale) these
flowers develop into small cones during the first season, as a rule completing
their growth and maturing their seeds at the end of the second summer. Ripe
cones vary from an inch in length and three-fourths inch in diameter, to 2
feet in length and 6 or 8 inches in diameter. The seed of most pines bears a
thin papery wing at one end. In a few species, however, the seed has only the
rudiment of a wing, which remains attached to the cone scale when the seed
is shed. The piilon or "nut" pines bear wingless seeds. Pine seeds vary from
one-half the size of a kernel of wheat to nearly the size of a small hazel nut.
Seeds of the " nut " pines are gathered by western Indians for food. The
needle-like foliage of pines varies from an inch to 14 or 15 inches in length.
Seed-leaves (cotyledons) of pines are needle-shaped and from 3 to 15 in number.
Succeeding these, pine seedlings produce temporary or primary leaves, which
are single; but later, commonly at the beginning of the second year, they begin
to bear their leaves in clusters. Leaves are borne in clusters during the
remainder of the tree's life.
The pines are among our most important commercial trees. Because they
have straight, unbranched, cylindrical trunks, they furnish large amounts of
excellent saw timber, without waste. Pine timber is widely used for all construction
purposes on account of its straight grain, strength, and other qualities.
The naval stores used in the United States, as well as the large quantities
exported to other countries, are derived by distillation from the crude resin of
the more resinous-wooded pines. Recently the wood of stumps and old logs is
being distilled for turpentine. Some 70 species of pines are known in the world.
Thirty-four pines inhabit the United States, 17 of which occur in the Pacific
region.
Pines are of ancient origin, some of them having existed in the Cretaceous
and Miocene periods in North America and Europe.
WHITE PINES.
Western White Pine; Silver Pine.
Pinus monticola Dougl.
DISTINGUISHING CHARACTERISTICS.
This species is more commonly called " white pine " where it is cut for lumber.
The name western white pine is proposed for this tree in order to distinguish
it from the eastern white pine (Pinus strobus).