Studies of Trees. Jacob Joshua Levison
needles to each cluster of the white pine. They are bluish green, slender, and about four inches in length.
At a distance the tree may be told by the right angles which the branches form with the main trunk, Fig. 3. No other pine shows this character.
Form and size: A tall tree, the stateliest of the evergreens.
Range: Eastern North America.
Soil and location: Prefers a deep, sandy soil, but will grow in almost any soil.
Enemies: Sucking insects forming white downy patches on the bark and twigs, the white pine weevil, a boring insect, and the white pine blister rust, a fungus, are among its principal enemies.
Fig. 3.—The White Pine.
Value for planting: Aside from its value as an ornamental tree, the white pine is an excellent tree to plant on abandoned farms and for woodlands and windbreaks throughout the New England States, New York, Pennsylvania, and the Lake States.
Commercial value: The wood is easily worked, light, durable, and will not warp. It is used for naval construction, lumber, shingles, laths, interior finish, wooden ware, etc.
Other characters: The fruit is a cone, four to six inches long.
Comparisons: The tree is apt to be confused with the Bhotan pine (Pinus excelsa), which is commonly grown as an ornamental tree. The Bhotan pine, however, has needles much longer and more drooping in appearance.
The Pitch Pine (Pinus rigida)
Distinguishing characters: Here there are three needles to each cluster, Fig. 4. They are dark, yellowish-green needles about four inches long. The rough-looking branches of the tree may be seen studded with cones throughout the year, and clusters of leaves may be seen sprouting directly from the trunk of the tree; see Fig. 5. The last two are very characteristic and will distinguish the tree at a glance.
Form and size: It is a low tree of uncertain habit and extremely rough looking at every stage of its life. It is constantly full of dead branches and old cones which persist on the tree throughout the year.
Range: Eastern United States.
Soil and location: Grows in the poorest and sandiest soils where few other trees will grow. In New Jersey and on Long Island where it is native, it proves so hardy and persistent that it often forms pure stands excluding other trees.
Fig. 4.—Twig of the Pitch Pine.
Enemies: None of importance.
Value for planting: Well adapted for the sea coast and other exposed places. It is of extremely uncertain habit and is subject to the loss of the lower limbs. It frequently presents a certain picturesqueness of outline, but it could not be used as a specimen tree on the lawn.
Fig. 5.—The Pitch Pine.
Commercial value: The wood is coarse grained and is used for rough lumber, fuel, and charcoal.
Other characters: The fruit is a cone one to three inches long, persistent on the tree for several years.
The Scotch Pine (Pinus sylvestris)
Distinguishing characters: There are two needles to each cluster, and these are short compared with those of the white pine, and slightly twisted; see Fig. 6. The bark, especially along the upper portion of the trunk, is reddish in color.
Form and size: A medium-sized tree with a short crown.
Range: Europe, Asia, and eastern United States.
Soil and location: Will do best on a deep, rich, sandy soil, but will also grow on a dry, porous soil.
Enemies: In Europe the Scotch pine has several insect enemies, but in America it appears to be free from injury.
Value for planting: Suitable for windbreaks and woodland planting. Many excellent specimens may also be found in our parks.
Commercial value: In the United States, the wood is chiefly used for fuel, though slightly used for barrels, boxes, and carpentry. In Europe, the Scotch pine is an important timber tree.
Comparisons: The Scotch pine is apt to be confused with the Austrian pine (Pinus austriaca), because they both have two needles to each cluster. The needles of the Austrian pine, however, are much longer, coarser, straighter, and darker than those of the Scotch pine; Fig. 1. The form of the Austrian pine, too, is more symmetrical and compact.
Fig. 6.—Twig of the Scotch Pine.
The red pine (Pinus resinosa) is another tree that has two needles to each cluster, but these are much longer than those of the Scotch pine (five to six inches) and are straighter. The bark, which is reddish in color, also differentiates the red pine from the Austrian pine. The position of the cones on the red pine, which point outward and downward at maturity, will also help to distinguish this tree from the Scotch and the Austrian varieties.
Group II. The Spruce and Hemlock
How to tell them from other trees: The spruce and hemlock belong to the evergreen class and may be told from the other trees by their leaves. The characteristic leaves of the spruce are shown in Fig. 9; those of the hemlock in Fig. 10. These are much shorter than the needles of the pines but are longer than the leaves of the red cedar or arbor vitae. They are neither arranged in clusters like those of the larch, nor in feathery layers like those of the cypress. They adhere to the tree throughout the year, while the leaves of the larch and cypress shed in the fall.
The spruces are pyramidal-shaped trees, with tall and tapering trunks, thickly covered with branches, forming a compact crown. They are widely distributed throughout the cold and temperate regions of the northern hemisphere, where they often form thick forests over extended areas.
There are eighteen recognized species of spruce. The Norway spruce has been chosen as a type for this group because it is so commonly planted in the northeastern part of the United States.
The hemlock is represented by seven species, confined to temperate North America, Japan, and Central and Western China.
Fig. 7.—The Norway Spruce.
How to tell them from each other: The needles and branches of the spruce are coarse; those of the hemlock are flat and graceful. The individual leaves of the spruce, Fig. 9, are four-sided and green or blue