The white pine (see illustrations, [pages 214-215]) is the only pine east of the Rocky Mountains that bears its leaves in bundles of five. This semi-decimal plan is found in three western soft pines and two western hard pines; but in the East, a native tree with needles in fives, leaves no doubt as to its name. From a distance this plan of five can be seen in the five branches that form a platform each year around the central shaft.
Study a sapling pine and you see in its vigorous young growth the fulfillment of nature's plan, before storms have broken any of the branches and changed the mathematics of the pattern. Stroke the flexible, soft leaves that sway graceful and lithe in the wind. If it is spring, note that the terminal bud has pushed out, and around it five-clustered buds are forming a circle of shoots. In autumn, after the season's growth is finished, each twig ends in a single bud, with a whorl of five buds around it. From the ground upward, count the platforms of branches. Each whorl of five marks a year in the tree's growth. The terminal bud carries the height a foot or two upward, and its surrounding five buds grow in the horizontal plane, forming the last and smallest platform of leafy shoots. Each branch is a year younger than the shoot that bears it. Note throughout this little tree the plan of five, from leaf cluster to largest branch.
Now go to the largest white pine in your neighborhood, study the plan of five in this tree, and find out the reason for any failures. Notice the conflict between the branches in the close platforms. Find branches where this conflict is in progress. Pick out the winner. Read the age of the tree by the platforms of branches on the trunk.
No evergreen is more beautiful than a white pine grown in rich soil in a situation sufficiently sheltered to defend its supple branches from breakage by severe winds. Its soft, plume-like twigs are dark blue-green, with pale lines lining each individual leaf. The young shoots are yellowish green, and they lighten in a wonderful manner the sombre coloring of the older foliage. At the bases of the new shoots cluster the staminate catkins, in early June. Yellow and becoming loose and pendulous as the wind shakes them, they are soon empty of their abundant pollen, which drifts like gold dust and fills the air. Among the youngest leaves, toward the end of the shoot, the purplish rosy lips of the erect pistillate cone-flowers catch the dust from neighbor trees, and their naked ovules absorb it and set seed. Close shut are the lips again, against any other invasion, while these ovules mature. We shall find them standing erect until autumn, but next season they hang down with their added weight, and at the end of the second summer the scales change from green to brown, open and give their ripe winged seeds to the wind for distribution. Because the tree is biennial-fruited, it always carries two sizes of cones. The large ones are one year older than the small ones. Ripe cones are five to ten inches long, with thin, broad, unarmed scales, squarish at the tips.
The most hopeful phase of the white pine problem to-day is the fact that new forests are coming up naturally where the early lumbering deforested great tracts in the Eastern states. Careful forestry improves upon nature's method, and so the pines are being restored on land unfit for agricultural crops. White pine is one of the most profitable timber crops to plant at the present time.
The Mountain Pine
P. monticola, D. Don.
The mountain pine is scattered through mountain forests from the Columbia River Basin in British Columbia to Vancouver Island, along the western slopes of the Rocky Mountains to northern Montana and Idaho, and south along the Sierra Nevada and Cascade ranges in Washington and Oregon, well into California. From the bottom lands of streams, where it is most abundant and reaches a height of one hundred to one hundred and fifty feet, and a trunk diameter of five to eight feet, it climbs to elevations of eight to ten thousand feet on the California Sierras. The bark of young trees and on the branches of old ones is smooth and pale-gray. The leaves, five in the bundles, range from one to four inches in length, stiff, blue-green, whitened by two to six stripes on the inner side. The cones are twelve to eighteen inches long, with thickened, pointed scales ending in an abrupt beak. The larger cone, denser, stiffer foliage, and the white bark make this white pine of the western mountains a great contrast to the Eastern white pine.
Unlike many trees whose size diminishes with increase in altitude, this white pine grows to majestic size at altitudes of nearly two miles, its noble figure more striking and impressive because of the dwindling size of its companions on the mountain-sides. The lumberman looks with despair upon these giant white pines, quite out of his reach.
In the Arnold Arboretum in Boston a fine seedling specimen of this western silver pine fruited when but twelve feet high, and proves vigorous and altogether happy in this absolutely changed climatic environment. In Europe the same success attends the cultivation of these trees, which have become very popular in parks and private grounds. Their introduction into our Eastern states can now be assured of success.