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.

[Illustration:  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.

[Illustration:  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 on the under side, while those of the hemlock, Fig. 10, are
    flat and are marked by two white lines on the under side.

THE NORWAY SPRUCE (Picea excelsa)

Distinguishing characters:  The characteristic appearance of the
    full-grown tree is due to the drooping branchlets carried on main
    branches which bend upward (Fig. 7).