154 
WAYSIDE AND WOODLAND TREES. 
The leaves are flat and slender, not in bundles, as in the 
Scots Pine, but arranged along the branchlets in two or three 
dense ranks. They are dark, rich green above, about an inch 
long, and on the flattened underside there is a bluish-white 
stripe on each side of the midrib, which gives a silvery ap- 
pearance to the foliage when upturned, as is usual on the 
fertile branches. These leaves endure from six to nine years. 
The flowers appear in May at the tips of the branches. The 
male flowers are about three-quarters of an inch long, and consist 
of two or three series of overlapping scales, enclosing the yellow 
stamens. The cones are cylindrical, with a blunt top, always 
erect, 6 to 8 inches long, and from i j to 2 inches in diameter. On 
the back of each of the broad scales there is a long, slender, 
pointed bract, which extends beyond the scale and turns down- 
ward. At first these cones are green, then become reddish, and 
when mature are brown ; but maturity is not reached until 
eighteen months after their appearance. The angular seeds are 
furnished with a broad wing twice their length. They are shed 
by the cones in the spring following their maturity, the scales 
falling at the same time and leaving the core of the cone on 
the tree. 
As a rule, the tree does not produce fertile seeds until it is 
about forty years of age, but seedless cones are formed from 
its twentieth year. Although the flowers of both sexes are 
found on the same tree, it may be that for a series of years 
only cones are produced. Until the Silver Fir is about twelve 
years old its growth is slow, and its annual increase is only 
a few inches, but later it will be as many feet. During this 
early stage spring frosts often destroy the leader-shoot, but 
its place is taken by another shoot, and soon the symmetry 
of the tree is restored. If this occurs at a later stage, how- 
ever, the tree bears evidence of it in a forked trunk. It is a 
deep-rooting species, with a branching tap-root, and succeeds 
best in an open soil that is moist without being wet. 
