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. [Illustration: Fig. 8] 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. A bushy tree, with a short trunk rarely more than a foot in diameter and a broad round-topped head, usually 15°—20° high, stout spreading branches, and slender dark orange-colored branchlets covered at first with matted pale deciduous hairs, dark brown and sometimes nearly black at the end of five or six years; in sheltered cañons on the mountains of Arizona and in Lower California occasionally 50° or 60° tall. Bark about ½′ thick, irregularly divided by remote shallow fissures and separated on the surface into numerous large thin light red-brown scales. Wood light, soft, close-grained, pale clear yellow. The large oily seeds are an important article of food in northern Mexico, and are sold in large quantities in Mexican towns. Distribution. Mountain ranges of central and southern Arizona, usually only above elevations of 6500°, often covering their upper slopes with open forests; in an isolated station on the Edwards Plateau on uplands and in cañons at the headwaters of the Frio and Nueces Rivers, Edwards and Kerr Counties, Texas; on the Sierra de Laguna, Lower California, and on many of the mountain ranges of northern Mexico; passing into the following varieties differing only in the number of the leaves in the leaf-clusters, and in their thickness.