as an ornamental tree.

The Colorado blue spruce (Picea parryana or Picea pungens) which is commonly used as an ornamental tree on lawns and in parks, can be told from the other spruces by its pale-blue or sage-green color and its sharp-pointed, coarse-feeling twigs. Its small size and sharp-pointed conical form are also characteristic.

It grows to a large size in Colorado and the Middle West. In the Eastern States and in northern Europe where it is planted as an ornamental tree, it is usually much smaller.

Fig. 9.—Twig of the Norway Spruce.

Hemlock (Tsuga canadensis)

Distinguishing characters: Its leaves are arranged in flat layers, giving a flat, horizontal and graceful appearance to the whole branch (Fig. 8). The individual leaves are dark green above, lighter colored below, and are marked by two white lines on the under side (Fig. 10).

The leaves are arranged on little stalks, a characteristic that does not appear in the other evergreen trees.

Form and size: A large tree with a broad-based pyramidal head, and a trunk conspicuously tapering toward the apex. The branches extend almost to the ground.

Range: The hemlock is a northern tree, growing in Canada and the United States.

Soil and location: Grows on all sorts of soils, in the deepest woods as well as on high mountain slopes.

Enemies: None of importance.

Value for planting: The hemlock makes an excellent hedge because it retains its lowest branches and will stand shearing. In this respect it is preferable to the spruce. It makes a fair tree for the lawn and is especially desirable for underplanting in woodlands, where the shade from the surrounding trees is heavy. In this respect it is like the beech.

Commercial value: The wood is soft, brittle, and coarse-grained, and is therefore used mainly for coarse lumber. Its bark is so rich in tannin that it forms one of the chief commercial products of the tree.

Other characters: The fruit is a small cone about ¾ of an inch long, which generally hangs on the tree all winter.

Fig. 10.—Twig of the Hemlock.

Group III. The Red Cedar and Arbor-Vitae

How to tell them from other trees: The red cedar (juniper) and arbor-vitae may be told from other trees by their leaves, which remain on the tree and keep green throughout the entire year. These leaves differ from those of the other evergreens in being much shorter and of a distinctive shape as shown in Figs. 12 and 13. The trees themselves are much smaller than the other evergreens enumerated in this book. Altogether, there are thirty-five species of juniper recognized and four of arbor-vitae. The junipers are widely distributed over the northern hemisphere, from the Arctic region down to Mexico in the New World, and in northern Africa, China, and Japan in the Old World. The arbor-vitae is found in northeastern and northwestern America, China, and Japan. The species mentioned here are those commonly found in America.

How to tell them from each other: The twigs of the arbor-vitae are flat and fan-like as in Fig. 13; the twigs of the red cedar are needle-shaped or scale-like as in Fig. 12. The foliage of the arbor-vitae is of a lighter color than that of the red cedar, which is sombre green. The arbor-vitae will generally be found growing in moist locations, while the red cedar will grow in dry places as well. The arbor-vitae generally retains its lower branches in open places, while the branches of the red cedar start at some distance from the ground.

Red Cedar (Juniperus virginiana)

Fig. 11.—The Red Cedar.

Distinguishing characters: The tree can best be told at a glance by its general form, size and leaves. It is a medium-sized tree with a symmetrical, cone-like form, Fig. 11, which, however, broadens out somewhat when the tree grows old. Its color throughout the year is dull green with a tinge of brownish red, and its bark peels in thin strips.

Fig. 12(a).—Twig of Young Cedar.

Fig. 12(b).—Twig of Cedar (Older Tree).

Leaf: In young trees the leaf is needle-shaped, pointed, and marked by a white line on its under side, Fig. 12(a). In older trees it is scale-like, Fig. 12(b), and the white line on its under side is indistinct.

Range: Widely distributed over nearly all of eastern and central North America.

Soil and location: Grows on poor, gravelly soils as well as in rich bottom lands.

Enemies: The “cedar