[Illustration: _Pl. 160._ Bole of Spruce Fir.]
Although we are compelled to class the Spruce among introduced species, it can lay claim to have been one of the older forest trees of Britain, for the upper beds of the Tertiary formations contain abundant evidence that the Spruce was a native here when those strata were laid down. Of its modern introduction there is no record, but from mention of it by Turner in his "Names of Herbes in Greke, Latin, Englishe, etc.," we know that it was at some date anterior to the publication of that work (1548). It is widely distributed as a native tree throughout the continent of Europe, with the exception of Denmark and Holland. It is the principal forest tree on the elevated tracts of Germany and Switzerland, and on the central Alpine ranges it reaches an altitude of 6500 feet. It is an extremely variable tree, but we cannot here deal with the varieties beyond saying that two principal forms, different in habit and in timber, are outwardly distinguished by one having red, the other green, cones.
The Spruce Fir is a tall and graceful tree with tapering trunk, 120 to 150 feet in height, though in this country its more usual stature, when full-grown, would be about 80 feet high, with a bole circumference of about 9 feet. At first covered with thin, smooth, warm-brown bark, in later life this breaks up into irregular scales, thin layers of which are cast off. Instead of a bushy crown, such as we see in the Silver Fir, the Spruce ends in a delicate spire, so familiar in the Christmas-tree, which is a Spruce Fir in the nursery stage. The branches are in very regular tiers from base to summit, and the branchlets go off almost opposite each other, densely clothed with the short grass-green needles. These are from a half to three-quarters of an inch in length, four-sided, and ending in a fine sharp point. They endure for six or seven years.
The flowers are produced near the ends of last year's shoots, those with stamens being borne singly or in clusters of two or three. They are about three-quarters of an inch in length, and of a yellow colour, tinged with pink. The cones, which hang downwards, are almost cylindrical, about 5 inches long and 1½ inches in diameter. The pale brown scales are thin, and loosely overlap. The seeds, of which there are two under each scale, are very small, with a transparent brown wing, five times the length of the seed. The flowers appear in May, and the seeds are not ripe until nearly a year later.