NATIONAL PARK SERVICE Forests of Yosemite, Sequoia, and General Grant National Parks

ALPINE SPECIES.

Among the alpine species there are two white pines, the western white pine (Pinus monticola) and the white-barked pine (Pinus albicaulis). The white-barked pine (fig. 16) is always a timber-line tree, growing scattered and stunted among the rocks. Its leaves are clustered in conspicuous bunches at the ends of its branches. Its cones are from 2 to 3 inches long.

FIG. 16.—White-bark pine (Pinus albicaulis) in its characteristic mountain habitat. Photograph by A. H. Denman.

The western white pine (fig. 17) in Idaho and Washington grows at moderate elevations and is a large and important timber tree. In the central Sierras it is found only at high elevations. Here it grows to diameters of 5 feet, but the height is usually not more than 100 feet. Its cones are much larger than those of the white-barked pine, being from 5 to 10 inches long.

FIG. 17.—Western white pine (Pinus monticola). Diameter 24 inches, height 50 feet.

The mountain hemlock (Tsuga mertensiana) is a peculiar little tree of the high snows and rocks (figs. 18 and 19). Its leaves have a short but distinct stem, like other hemlocks, in contrast to the stemless leaves of the spruces and firs. But instead of the thin, flat, two-ranked leaves of other hemlocks, this one has thick, angular leaves, growing all around the twigs. It is usually from 10 to 20 inches in diameter and from 25 to 60 feet tall, although in favorable situations it sometimes grows to a diameter of 40 inches and a height of 125 feet. On bleak summits it is often only a few feet high, or sprawling on the ground. Despite the hard conditions and its small size, it clings to life and grows to a great age, but there is no reliable knowledge in regard to its growth and length of life.

FIG. 18.—Mountain hemlock (Tsuga mertensiana). Photograph, by Geo. O. Caesar.

FIG. 19.—A wind-swept mountain hemlock. Photograph by A. H. Denman.