P. flexilis, James
The Rocky Mountain white pine inhabits mountain slopes from Alberta to Mexico, including the Sierra Nevada range. In northern New Mexico and Arizona it occasionally reaches eighty feet in height, but ordinarily does not exceed fifty. Its rounded dome, as broad as an oak, bravely dares the wind on exposed cliffs, and crouches as a stunted shrub at altitudes of twelve thousand feet. The "limber pine" it is called, from the toughness of its fibre, which alone enables its long limbs to sustain the whipping they get. The leaves form thick, beautiful dark-green tufts, which are not shed until the fifth or sixth year. The cones are three to ten inches long, purplish; scales rounded, abruptly beaked at the apex; narrow wings entirely surround the seeds, which fall in September.
This is the lumber pine of the semi-arid ranges of "The Great American Desert"; the main dependence of builders, too, on the eastern slopes of the Rockies in Montana.
The White-bark Pine
P. albicaulis, Engelm.
The white-bark pine is a rippled, gnarled, squatting tree, whose matted branches, cumbered with needles and snow, make a platform on which the hardy mountain-climber may walk with safety in midwinter. It offers him a springy mattress for his bed, as well. The trunk is covered with snowy bark that glistens like the ice-mantle that lies on the treeless mountain-side just above the timber line.
From a twelve-thousand-foot elevation on the Rocky Mountains, in British Columbia and south to the Yellowstone, the tree clambers down to the five-thousand-foot line, where it sometimes attains forty feet in height; its dark green, rigid leaves persist from five to eight years, always five in a bundle, and never more than two and a half inches long. The cones, horny-tipped, dark purple, one to three inches long, are ripe in August; the large sweet seeds are gathered and eaten by Indians. In California the tree's range extends into the San Bernardino Mountains.
THE TWO "FOXTAIL" PINES
Two Western pines are distinguished by the common name "foxtail pine," because the leaves are crowded on the ends of bare branchlets. P. Balfouriana, M. Murr., has stiff, stout dark green leaves with pale linings. The tree is wonderfully picturesque when old, with an open irregular pyramid, on the higher foothills of the California mountains, or crouching as an aged straggling shrub at the timber-line. Its cones are elongated, the scales thickened and minutely spiny at tip.
The second five-leaved foxtail pine is P. aristata, Engelm., also called the "prickle-cone pine," from the curving spines that arm the scales of the purplish brown fruits. This is a bushy tree, with sprawling lower branches and upper ones that stand erect and are usually much longer, giving the tree a strange irregularity of form. The leaves are short and crowded in terminal brushes. From a stocky tree forty feet high, to a shrub at the timber line, this tree is found near the limit of tree growth, from the outer ranges of the mountains of Colorado to those of southern Utah, Nevada, northern Arizona and southeastern California. In Eastern parks it is occasionally seen as a shrubby pine with unusually interesting, artistic cones.