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

FOREST TREES OF THE PACIFIC SLOPE. 39
lower ones. Somewhat larger occasionally. The bark of old trunks is a dull
reddish brown and is rather shallowly furrowed, the main flat ridges irregularly
connected by narrower slanting divisions, whereas the limbs, as well as
the trunks of small trees, are smooth and chalky-white. The deep green foliage
is densely clustered at the ends of the twigs, the needles seeming to be pressed
down; in this respect closely resembling the true fox-tail pine. F ive leaves,
about II to 11 inches long, are borne in a cluster (fig. 10). Leaves of each
season's growth persist approximately twelve to fourteen years. Ripe cones,
matured at the end of the second season, are from 24 to about 38 inches long,
deep chocolate brown with a purplish tinge, the end of each cone seale tipped
with a bristle-like, very fragile prickle (fig. 10) ; unexposed parts of the scales,
clear reddish brown. Seeds (fig. 10, a), pale brown with irregular black spots,
are shed from about the last of September to the middle of October. Seed leaves,
6 to 7. Wood, pale brownish red. light, usually rather coarse-grained, soft, and
very brittle. On account of the poor form of the tree the wood is of no economic
use; sometimes employed for minor local purposes in the region of greatest
abundance.
LONGEVITY.-Little is known of the ages attained. Trees from 16 to 20 inches
in diameter are from 200 to 25(1 years ola.
RANGE.
On high peaks from Colorado to southern Utah, central and southern Nevada, se utheastern
California, and northern Arizona.
CALIFoRNIA.-Known only on the Panamint Range at 7,800 to 10,800 feet, and also
on the adjacent White and Inyo Mountains. Reported to be on the high Sierras east
of Yosemite Park and on Mount 1Pinos in Ventura County, but these stations require
further investigation.
Range in Rocky Mountains will be described in a future bulletin.
OCCURRENCE.
Ridges, rocky ledges, and (mainly) south slopes, here often predominating. On thin,
rocky soils; often on volcanic soils of cinder cones Usually in isolated situations
where snow melts early and evaporation is rapid, so that the tree is subjected to more
or less prolonged dryness of soil during summer. Rarely forms pure forest, but usually
is found in scattering stand with grassy ground cover and little or no underbrush. At
lower altitudes, with limber and yellow pines, white fir; higher up, in thickest part of
its belt, associated only with limber pine.
CLIMATIC CONDITIOXs.-Seasonal range of temperature endured from about -50' to
05' F. Radiation rapid and daily range of temperature great. Annual precipitation
from 20 to 30 inches, and very largely snow. Rainfall irregularly distributed; dryest
months, July and August. Atmosphere dry.
TOLERAXcE.-Appalently intolerant of shade, never forming dense stands.
IRPRODUCTIOx -Trees bear cones when about 20 years old, and seed is produced practically
every year thereafter. There appear to be regular seed years in which seed
crop is heavier than usual. Seeding takes place to a distance of at least 600 feet from
mother trees. Seeds eaten by rodents and quickly killed by fire. Best seed-bed is
exposed mineral soil, but seedlings often grow in grats and litter; they thrive best onslopes
with little underbrush.
Foxtail Pine.
Pinus balfouriana Murray.
DISTINGUISHING CHARACTERISTICS.
Distinguished from its associates by a narrow, bushy crown of irregularly
long upper branches, the smooth bark of which is chalky-whilte. The deeply
fissured, bright cinnamon-brown bark of mature trunks (with squarish plates)
is also very characteristic. Height, from 35 to occasionally 60 feet, and diamneter,
from 10 to 30 inches. Trunks are clothed with short branches, below the
long upper ones, for one-half or two-thirds of their length; fairly straight, but
rough with knots and the swelled bases of branches, and usually tapering
rapidly in the upper half. The foliage, which is a bright blue-green, covers the