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

FOREST TREES OF THE PACIFIC SLOPE. 121
spruce and alpine fir. Owing to great tolerance, it has a close branching habit, and
the trunks clean poorly. Young growth survives long suppression under heavy shade
(with slow progress) and recovers readily when overhead light is admitted.
RFPRoDUcTioN.-Fairly prolific seeder. Good seed yeara occur at irregular intervals
(two to three years or more), but some seed is produced every year. Seed of only moderately
high rate of germination, often under 40 per cent, and with only transient
vitality. Seed production begins mainly at fairly advanced age; in dense stands polewood
trees seed when leaders have reached full light. Seed production continues for
many years, but is more abundant during rapid height growth than at maturity. Character
of seed bed apparently of little importance, germination taking place on heavy
litter and humus, as well as in mineral soil; but fairly abundant soil moisture is essential
for establishing seedlings. Indifference to kind of seed bed renders it aggressive, for
reproduction occurs over denuded lands as well as under its own shade.
Bristlecone Fir.
Abies venusta (Dougl.) Koch.
DISTINGUISHING CHARACTERISTICS.
Bristlecone fir, which is rare and little known, is unique in all of its characters,
the most striking of which is, perhaps, its dense Indian-club-shaped crown,
which very often extends to the ground, and ends in a long, exceedingly narrow,
sharp point. The sharp spires and deep lustrous green foliage are so distinctive
that the tree can be recognized among its associates several miles away. It is
ordinarily from 60 to 100 feet high, or occasionally somewhat taller, and from 20
to 30 inches in diameter. The trunk, rarely clear of branches for more than a
few feet, tapers rapidly to the slender, erect leader. All of the branches, which
grow from the trunk in irregular circles, droop conspicuously, while their extremely
long, whip-like side branchlets hang like tasseled cords among the
branches. The bark of young trees is thin, smooth, and a leaden gray. On older
trees it is comparatively thin, at most seven-eighths inch thick, and is irregularly
broken by shallow vertical seams into flat plates, which are hard and firm.
The bark of old trunks is light russet brown on the outside and clear red-brown
within. The dense bright foliage is deep yellow-green. The long flat leaves (fig.
45), white-lined underneath, with their keen points are very characteristic. By
a twist in their stems, leaves of lower branches (which are less densely leaved
than upper ones) appear to grow from two opposite sides of the branches, while
leaves from the middle and upper crown branches are rather densely arranged,
mainly on the tops of the branches. The thinly scattered leaves of leaders (fig.
46) stand out straight, in strong contrast to the much less spreading habit of
the other leaves. Leaves vary in length froni about 1i to 2 inches. Lower
branch leaves are usually longer than those from the upper crown branches.
The large conspicuously pointed winter leaf buds are bright light chestnut-color,
and without resin. The cones (fig. 47), which ripen late in August and break
up in September, are one of the remarkably distinct features of this fir, particularly
in the long needle-like points of their scale-bracts, which protrude from
among the cone-scales. Cones are from 24 to 37 inches long, and have at maturity
a faint purplish brown color. Seeds are deep chestnut-brown with shiny,
light, purplish tinged, brown wings (fig. 47, c). Seed leaves, 7. Wood of
this fir is heavier than that of any other of our firs. It is light yellowish brown,
moderately soft, but very firm, and usually coarse-grained. It is least like any
of the soft, light fir woods. There is nothing to commend it for commercial uses,
for which at present it is barred on account of the exceedingly small number
of trees in existence. The tree is, however, of the greatest importance in forming
much needed protective cover for the scantily wooded slopes and dry canyons
which it naturally inhabits. For this reason, and on account of its extreme