forest trees of the pacific slope. 65 



Reported from San Jacinto Mountains. Limited area on Mount Shasta at 4,000 to 5,600 

 feet, between Panther and Mud creeks ; eastward to Fall River. West slopes of northern 

 Sierras, at 1,500 to 3,000 feet — occasionally to 4,000 feet, and southward to Yosemite 

 National Park (?). Forest Hill (between forks of American River), at 2,500 feet eleva- 

 tion ; north slope of Merced River (T. 3 S., R. 18-19 E.) in Sierra National Forest 

 (north) ; Lake Tahoe National Forest, only near Lynchburg, at 4,000 feet, and on ridge 

 above Horse Shoe Bar (T. 13 N., R. 12 E.) 



OCCURRENCE. 



Usually on dry, exposed, steep southeastern slopes, but often in deep gulches and pro- 

 tected ravines. On poor, dry, rocky, or gravelly and sandy soils. Next to digger 

 pine it is the least fastidious of its kind regarding soil moisture. Frequently forms 

 extensive pure forests, especially in Oregon ; in foothills, it grows mainly in groups 

 or singly, while in San Bernardino Mountains it is sparingly scattered in western 

 yellow pine forests, with bigcone spruce, sugar pine, white fir, incense cedar, Coulter 

 pine, and oaks. 



Climatic Conditions. — Endures seasonal temperature of from about zero to 95° F., 

 with occasional heavy snows and an annual rainfall up to 45 inches. 



Tolerance. — Next to digger pine, the least tolerant of Pacific coast pines. 



Reproduction. — Abundant annual seeder, bearing cones at very early age. Seed with 

 high rate of germination and with very persistent vitality in cones, no matter how old 

 the cones are. Old trees often bear over 3.5 pounds of seed. Few cones open except 

 by the aid of fire, which is nearly always followed by abundant reproduction. Seed germi- 

 nates in the most barren soils, and seedlings are hardy from the start. 



Pricklecone Pine; Bishop's Pine. 

 Pinus muricata Don. 



DISTINGUISHING CHARACTERISTICS. 



Pricklecone or bishop's pine is a little-known species which, on account of 

 its endurance of conditions most unfavorable to the growth of other pines, 

 deserves the forester's careful attention. Ordinarily it is from 30 to 60 feet 

 high and from 12 to 20 inches in diameter; trees from 75 to 80 feet high 

 and from 24 to 36 inches thick occur rarely. Young trees in an open or scat- 

 tered stand have dense, pyramidal crowns and short, clear trunks. Older trees 

 under such conditions bear a dense crown rounded at the top, with stout 

 branches still extending low to the ground. In dense stands, in which it fre- 

 quently occurs, the crown is much the same, but shorter, and the trunk is 

 cleaner. The bark, early broken even on young trees, is deeply furrowed and 

 rough, with dull purple-brown scales. The deep yellow-green foliage is con- 

 spicuously dense on the extremities of the numerous branches. The stiff leaves 

 (fig. 24), 2 in a bundle, are from 34 to 54 inches long; usually 3 J or 4 inches. 

 Leaves of a season's growth fall from the branches during the second and third 

 summers. The cones (fig. 25), specially characterized by their indefinite per- 

 sistence, are mature inAugust of the second season, when their prickly scales are 

 shiny and a rich russet-brown. Many of them open and shed their seed in Sep- 

 tember and October, while some of them remain closed for a number of years. 

 A singular fact concerning the persistent cones is that they are rarely or never 

 embedded in the stems of the trees, as in the case of other pines with persistent 

 cones. The stems of the cones are broken and slowly drawn or forced from the 

 wood by each year's growth pushing against the base of the cone, which is 

 sometimes lightly held by the living bark. The seeds (fig. 25, a) are blackish 

 or very dark brown, with a roughish surface. Seed-leaves, usually 5. but often 

 4. Wood, light yellowish-brown, rather heavy and hard, moderately coarse- 

 grained ; of no commercial use. 



Longevity. — Little is known concerning the longevity of this pine, which 

 appears to grow rapidly in diameter for the first 40 or 50 years. Trees from 



