e is
broad at the base and tapers to the top, where it terminates in a
slender, pointed tip. At its upper limit it becomes a stunted shrub,
with wide extended branches resting on the ground.

The alpine fir bears upright clusters of deep-purple cones. It seeds
sparingly each year. The seasons of heavy seed production occur at
intervals of three or four years. The wood is soft and splits easily. It
is of no commercial value. The tree is easily killed by fire, which
blisters the thin bark and frequently springs into the drooping lower
branches.

GRAND FIR (ABIES GRANDIS.)[4]

The grand fir (fig. 14), like several other species, is generally given
the name of white fir on account of its smooth, light-colored bark. It
is a common tree in the river bottoms from British Columbia south to
northern California. In the Mount Rainier National Park it occurs up to
4,000 feet. The grand fir is a moisture-loving tree and is usually found
firmly rooted in deep alluvial bottom lands along the banks of streams.
With the Douglas fir, hemlock, and red cedar it forms the dense forest
characteristic of the lower mountain valleys.

In favorable conditions the grand fir grows to a height of from 100 to
200 feet and is a noble and stately tree. The trunk tapers rapidly and
bears a rounded pyramidal crown. In dense forests the trunk is clear for
half its height, but where the trees stand in the open it carries its
branches nearly to the ground. The leaves are a bright and shining
green. The large light-green cones mature early in the fall. The wood is
soft and very heavy before it is seasoned. It rots in a very short time
when laid on the ground. When dry it is white, coarse-grained, light,
and odorous. It is used for interior finish and for crates and packing
boxes, but is of little value commercially.

ENGELMANN SPRUCE (PICEA ENGELMANNI).

The Engelmann spruce (fig. 15) is a mountain tree ranging from British
Columbia to Arizona and New Mexico. It is common along the summit and on
the east side of the Cascade Range and occurs on the northeastern and
eastern slopes of Mount Rainier at elevations of from 3,500 to 6,000
feet.

This tree requires a moist soil and prefers cool northern exposures. Up
to 5,000 feet it commonly grows in sheltered basins at the head of
canyons and in stream valleys. At its upper limits it is common on flats
and depressions and about lakes on level summits. It avoids steep
mountain sides and exposed situat