A tree, usually 30°—40° or rarely 90° high, with a trunk generally 1°—2° or rarely 5° in diameter, short stout branches forming an open irregular pyramidal picturesque head, and long rigid more or less spreading puberulous, soon glabrous, dark orange-brown ultimately dark gray-brown or nearly black branchlets, clothed only at the extremities with the long dense brush-like masses of foliage. Bark thin, smooth, and milky white on the stems and branches of young trees, becoming on old trees sometimes ¾′ thick, dark red-brown, deeply divided into broad flat ridges. broken into nearly square plates separating on the surface into small closely appressed scales. Wood light, soft and brittle, pale reddish brown.
Distribution. California, on rocky slopes and ridges, forming scattered groves on Scott Mountain, Siskiyou County, at elevations of 5000°—6000°; on the mountains at the head of the Sacramento River; on Mt. Yolo Bally in the northern Coast Range, and on the southern Sierra Nevada up to elevations of 11,500°, growing here to its largest size and forming an extensive open forest on the Whitney Plateau east of the cañon of Kern River, and at the highest elevations often a low shrub, with wide-spreading prostrate stems.
7. [Pinus aristata] Engelm. Foxtail Pine. Hickory Pine.
Leaves stout or slender, dark green, lustrous on the back, marked by numerous rows of stomata on the ventral faces, 1′—1½′ long, often deciduous at the end of ten or twelve years or persistent four or five years longer. Flowers male dark orange-red; female dark purple. Fruit 3′—3½′ long, with scales armed with slender incurved brittle prickles nearly ¼′ long, dark purple-brown on the exposed parts, the remainder dull red, opening and scattering their seeds about the 1st of October; seeds nearly oval, compressed, light brown mottled with black, ¼′ long, their wings broadest at the middle, about ⅓′ long and ¼′ wide.
A bushy tree, occasionally 40°—50° high, with a short trunk 2°—3° in diameter, short stout branches in regular whorls while young, in old age growing very irregularly, the upper erect and much longer than the usually pendulous lower branches, and stout light orange-colored, glabrous, or at first puberulous, ultimately dark gray-brown or nearly black branchlets clothed at the ends with long compact brush-like tufts of foliage. Bark thin, smooth, milky white on the stems and branches of young trees, becoming on old trees ½′—¾′ thick, red-brown, and irregularly divided into flat connected ridges separating on the surface into small closely appressed scales. Wood light, soft, not strong, light red; occasionally used for the timbers of mines and for fuel.
Distribution. Rocky or gravelly slopes at the upper limit of tree growth and rarely below 8,000° above the sea from the outer range of the Rocky Mountains of Colorado to those of southern Utah, central and southern Nevada, southeastern California, and the San Francisco peaks of northern Arizona.
8. [Pinus cembroides] Zucc. Nut Pine. Piñon.
Leaves in 2 or 3-leaved clusters, slender, much incurved, dark green, sometimes marked by rows of stomata on the 3 faces, 1′—2′ long, deciduous irregularly during their third and fourth years. Flowers: male in short crowded clusters, yellow; female dark red. Fruit subglobose, 1′—2′ broad; seeds subcylindric or obscurely triangular, more or less compressed at the pointed apex, full and rounded at base, nearly black on the lower side and dark chestnut-brown on the upper, ½′—¾′ long, the margin of their outer coat adnate to the cone-scale.