SPRUCE AND BALSAM FIR TREES. 31 
trees results from the cessation of height growth in the leader and 
an elongation of the older, shorter, upper side branches. All of 
the branches, except the topmost, have a distinct downward and 
upward swing. The bark, peculiarly characteristic in this species, 
is smooth and ashy-brown, with chalky areas on young trunks and 
regularly and shallowly furrowed on older trees, the long, flat ridges 
still retaining splashes of gray-white. (PL XVIII.) The bark of 
very old trees is still more deeply but narrowly furrowed, the ridges 
being sharper and less conspicuously flecked with white and the 
general tone pale red-brown with an ashen tinge. In texture the 
bark is very hard, close, and horny. It is rarely over If inches thick 
on old trunks and scarcely an inch thick on trees from 18 to 20 
inches in diameter. 
The deep yellow-green shiny foliage of grand fir is somewhat thin 
in appearance because of the characteristic two-ranked arrange- 
ment of leaves on the lower branches. Leaves on these branches are 
flat, grooved above, blunt, and nearly always distinctly notched at 
their ends (PL XVI). They appear to grow only from two oppo- 
site sides of the branches, but many of the leaves are brought into 
this position by a twist at their bases. Leaves of the lower-crown 
branches are from about one- fourth inch to 2£ inches long. Leaves of 
the uppermost branches also are often notched; but here they are 
usually crowded together in a more or less upright position on the 
top sides of the sprays and are from about 1 to 1^ inches long 
(PL XVII). The scattered leaves of the leader are sharp or keenly 
pointed and from one-half to seven-eighths of an inch long. All 
leaves are conspicuously white on their under surfaces. The mature 
winter buds are covered with resin, and the twigs of the season are 
pale russet-brown and minutely hairy. 
The cones of this fir mature in early autumn, and are very char- 
acteristic in their clear, light yellow-green color and slender, cylin- 
drical form (PL XVII). They are about 2J to 4J inches long and 
about 1 to 1J inches in diameter. The bracts of the cone scales are 
relatively broad and usually squarish (truncated) at their upper 
ends (PL XVII, a), or occasionally somewhat heart-shaped or 
notched at the top end with a small tooth-like point extending from 
the center. The pale yellowish-brown seeds (PL XVII, 5, e) have 
shiny, faintly yellowish wings. The seed-leaves, which are very 
slender and pointed, are usually six in number, and about three- 
fourths of an inch long (PL XVII, d) . 
The wood of grand fir ranks fourth in weight among Eocky 
Mountain fir woods, a cubic foot of dry wood weighing about 22 
pounds. It is soft, but firm enough to be useful as lumber, moder- 
ately wide-ringed and straight-grained. In color it varies from pale 
10529°— Bull. 327—16 3 
