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 irregu- 

 larly connected by narrower slanting divisions, whereas the liinhs, 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 he pressed 

 down; in this respect closely resembling the true fox-tail pine. Five leaves. 

 about 1| to 1J 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 2J to about 3j inches long, 

 deep chocolate brown with a purplish tinge, the end of each cone scale 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 250 years old. 



RANGE. 



On high peaks from Colorado to southern Utah, central and southern Nevada, south- 

 eastern 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 Pinos 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 Conditions. — Seasonal range of temperature endured from about —50° to 

 05° F. Radiation rapid and daily range of temperature great. Annual precipitation 

 from 20 to ."10 inches, and very largely snow. Rainfall irregularly distributed; dryest 

 months, July ami August. Atmosphere dry. 



TOLERANCE. — Apparently intolerant of shade, never forming dense stands. 



Uwrodt'ction. — Trees bear cones when about 20 years old. and seed is produced prac- 

 tically 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 grass and litter; they thrive best on 

 slopes with little underbrush. 



Foxtail Pine. 

 Pi mix balfouriana Murray. 



DISTINGUISHING CHARACTERISTICS. 

 Distinguished from its associates by a narrow, bushy crown of irregularly 

 long upper branches, the smooth hark of which is chalky-white. 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 diam- 

 eter, 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 brandies, and usually tapering 

 rapidly in the upper half. The foliage, which is a bright blue-green, covers the 



