[Ill.u.s.tration: 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 coa.r.s.e-grained, and is therefore used mainly for coa.r.s.e 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 of an inch long, which generally hangs on the tree all winter.
[Ill.u.s.tration: 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 j.a.pan in the Old World. The arbor-vitae is found in northeastern and northwestern America, China, and j.a.pan. 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_)
[Ill.u.s.tration: 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.
[Ill.u.s.tration: 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 apple_," commonly found on this tree, represents a stage of the apple rust, and for that reason it is not desirable to plant such trees near orchards. Its wood is also sometimes attacked by small _boring insects_.
Value for planting: Its characteristic slender form gives the red cedar an important place as an ornamental tree, but its chief value lies in its commercial use.
Commercial value: The wood is durable, light, smooth and fragrant, and is therefore used for making lead-pencils, cabinets, boxes, moth-proof chests, shingles, posts, and telegraph poles.
Other characters: The _fruit_ is small, round and berry-like, about the size of a pea, of dark blue color, and carries from one to four bony seeds.
Other common names: The red cedar is also often called _juniper_ and _red juniper_.
Comparisons: The red cedar is apt to be confused with the _low juniper_ (_Juniperus communis_) which grows in open fields all over the world. The latter, however, is generally of a low form with a flat top. Its leaves are pointed and p.r.i.c.kly, never scale-like, and they are whitish above and green below. Its bark shreds and its fruit is a small round berry of agreeable aromatic odor.
ARBOR-VITAE; NORTHERN WHITE CEDAR (_Thuja occidentalis_)
Distinguishing characters: The *branchlets* are extremely *flat and fan-like*, Fig. 13, and have an agreeable _aromatic odor_ when bruised. The tree is an evergreen with a _narrow conical form_.
[Ill.u.s.tration: FIG. 13.--Twig of the Arbor-vitae.]
Leaf: Leaves of two kinds, one scale-like and flat, the other keeled, all tightly pressed to the twig (see Fig. 13).
Form and size: A close, conical head with dense foliage near the base.
Usually a small tree, but in some parts of the northeastern States it grows to medium size with a diameter of two feet.
Range: Northern part of North America.
Soil and location: Inhabits low, swampy lands; in the State of Maine often forming thick forests.
Enemies: Very seldom affected by insects.
Value for planting: Is hardy in New England, where it is especially used for hedges. It is also frequently used as a specimen tree on the lawn.
Commercial value: The wood is durable for posts, ties, and shingles. The bark contains considerable tannin and the juices from the tree have a medicinal value.
Other characters: The _fruit_ is a cone about inch long.
Other common names: Arbor-vitae is sometimes called _white cedar_ and _cedar_.
Comparisons: The arbor-vitae is apt to be confused with the true _white cedar_ (_Chamaecyparis thyoides_) but the leaves of the latter are sharp-pointed and not flattened or fan-shaped.
CHAPTER II
HOW TO IDENTIFY TREES--(Continued)