rally_,
thus making the twigs coarser to the touch than the twigs of the
hemlock or fir. In cross-section, the individual leaflet is
quadrilateral, while that of the pine is triangular.

Form and size: A large tree with a straight, undivided trunk and a
well-shaped, conical crown (Fig. 7).

Range: Northern Europe, Asia, northern North America.

Soil and location: Grows in cool, moist situations.

Enemies: The foliage of the spruce is sometimes affected by _red
spider_, but is apt to be more seriously injured by drought, wind,
and late frosts.

Value for planting: Commonly planted as an ornamental tree and for
hedges. It does well for this purpose in a cool northern climate,
but in the vicinity of New York City and further south it does not
do as well, losing its lower branches at an early age, and becoming
generally scraggly in appearance.

[Illustration: FIG. 8.--A Group of Hemlock.]

Commercial value: The wood is light and soft and is used for
construction timber, paper pulp, and fuel.

Other characters: The _fruit_ is a large slender cone, four to seven
inches long.

Comparisons: The _white spruce_ (_Picea canadensis_) may be told from
the Norway spruce by the whitish color on the under side of its
leaves and the unpleasant, pungent odor emitted from the needles
when bruised. The cones of the white spruce, about two inches long,
are shorter than these of the Norway spruce, but are longer than
those of the black spruce.

It is essentially a northern tree growing in all sorts of locations
along the streams and on rocky mountain slopes as far north as the
Arctic Sea and Alaska. It often appears as an ornamental tree as far
south as New York and Pennsylvania.

The _black spruce_ (_Picea mariana_) may be told from the other
spruces by its small cone, which is usually only about one inch in
length. In New England it seldom grows to as large a size as the
other spruce trees.

It covers large areas in various parts of northern North America and
grows to its largest size in Manitoba. The black spruce has little
value 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 twig