FOREST TREES OF THE PACIFIC SLOPE. 181 



OCCURRENCE. 



On dry exposed mesas, low, dry mountain slopes, and rather moist canyon bottoms 

 (where best tree form occurs), In dry, rocky, sandy, or gravelly soil, but often very 

 scanty in the latter sort. 



Nothing is known now of its silvical habits in Pacific region, where it is compara- 

 tively rare; but single trees or small groups are commonly scattered among piuon pine, 

 one-seed juniper, mountain mahogany, and narrow-leaf Cottonwood, in Rocky Mountain 

 range. 



Climatic Conditions, Tolerance, and Reproduction. — Not determined. In pro- 

 tected canyons and other sheltered sites, it appears to endure (in most soils) considerable 

 shade of broadleaf trees, closely resembling Juniperus virgintana in this respect. Usually 

 a prolific seeder. 



Western Juniper. 

 Juniperus occidontalis Hooker. 



DISTINGUISHING CHARACTERISTICS. 



Western juniper, a high mountain tree, is chiefly known simply as "juniper." 

 P>ecause of its uniformly higher range it is not likely to be confounded with the 

 California juniper of a much lower zone, which it resembles in general appear- 

 ance. Western juniper has a round-topped, open crown, extending to within a 

 few feet of the ground, and a short, thick, conical trunk. Height, from 13 to 20 

 or. less commonly, 30 feet; only rarely 60 feet or over: taller trees occur in pro- 

 tected situations ; diameter from 16 to 30 inches, exceptionally from 40 to 60 

 inches. The trunks, chunky and conical in general form, and with ridges and 

 grooves, are usually straight, even in the most exposed sites, but are sometimes 

 bent and twisted. With its stocky form this tree develops enormously long and 

 large roots which enable it to withstand unharmed the fierce winds common to 

 its habitat. There is rarely more than from 4 to 8 feet of clear trunk, while 

 huge lower branches often rise from the base and middle of the trunk like 

 smaller trunks. Of the other branches, some are large and stiff, standing 

 out straight or trending upward from the trunk, while many are short ones. Some- 

 times the top is divided into two or three thick forks, giving the tree a broader 

 crown than usual. In such cases, when the trees are growing in flats with deep 

 soil, the crowns are dense, symmetrical, round-topped, and conical, and extend 

 down to within 6 feet of the ground. Young trees have straight, sharply taper- 

 ing stems and a narrow, open crown of distant, slender, but stiff-looking, long, 

 upturned branches. Often in old age the branches are less vigorously developed 

 and droop at the bottom and middle of the crown, but their tips continue to 

 turn upward. The bark is a clear, light cinnamon-brown, one-half to 14, inches 

 thick, distinctly cut by wide, shallow furrows, the long flat ridges being con- 

 nected at long intervals by narrower diagonal ridges. It is firm and stringy. 

 Branchlets which have recently shed their leaves are smooth, and a clear red- 

 dish brown. The bark on them is then very thin, but later on it is divided into 

 loosely attached, thin scales of lighter red-brown. 



The short, pale ashy-green, scale-like leaves (figs. 71, 72) clasp the stiff twigs 

 closely, the longer, sharper leaves of young, thrifty shoots spreading slightly 

 only at their points. All leaves are prominently marked on the back by a glan- 

 dular pit, whitish with resin. Groups of three leaves clasp the twigs succes- 

 sively, forming a rounded stem with longitudinal rows of leaves. The leaves 

 produced each season die in about their second season, after which they are 

 gradually forced off by the growth of the branchlets. The "berries" (figs. 71, 

 72), one-fourth to one-third of an inch long, mature about the first of September 

 of the second year, when they are bluish black, covered with a whitish bloom ; 



