Cone Bearing Evergreens - Spruces
( Originally Published 1927 )
The distinguishing mark of spruce trees is the woody or horny projection on which the leaf is set. Look at the twigs of a tree which you think may be a fir or a spruce. Wherever the leaves have fallen, the spruce twig is roughened by these spirally arranged leaf-brackets. Leaf-scars on a fir twig are level with the bark, leaving the twig smooth. Spruce twigs are always roughened, as described above.
Most spruce trees have distinctly four-angled leaves, sharp-pointed and distributed spirally around the shoot, not two-ranked like fir leaves. They are all pyramidal trees with flowers and fruits of the coniferous type. The cones are always pendent and there is an annual crop. The wood is soft, not conspicuously resinous, straight-grained and valuable as lumber.
The genus picea comprises eighteen species, seven of which belong to American forests. These include some of the most beautiful of coniferous trees.
The Norway Spruce
Picea excelsa, Link.
The Norway spruce (see illustration, page 246) is the commonest species in cultivation. It is extensively planted for wind-breaks, hedges and shelter belts, where its long lower arms rest on the ground and the upper limbs shingle over the lower ones, forming a thick leafy shelter against drifting snow and winds.
The Black Spruce
P. Mariana, B. S. & P.
The black spruce is a ragged, unkempt dingy tree, with short drooping branches, downy twigs, and stiff dark blue-green foliage, scarcely half an inch long. Its cones, least in size of all the spruce tribe, are about one inch long and they remain on the branches for years.
Rarely higher than fifty feet, these scraggly undersized spruces are ignored by horticulturists and lumbermen, but the wood-pulp man has taken them eagerly. The soft weak yellow wood, converted into paper, needs very little bleaching. From the far North the species covers large areas throughout Canada, choosing cold bogs and swamp borders, or well-drained bottom lands. In the United States it extends south along the mountains to Virginia and to central Wisconsin and Michigan.
The Red Spruce
P. rubens, Sarg.
The red spruce forms considerable forests from Newfoundland to North Carolina, following the mountains and growing best in well-drained upland soil. This Eastern spruce is more deserving of cultivation than the one just described, for its leaves, dark yellow-green and shining, make the tree cheerful-looking. The slender downy twigs are bright red, and there is a warm reddish tone in the brown bark. The winter buds are ruddy; the flowers purple; and the glossy cones, one to two inches long, change from purple to pale reddish brown before they mature and drop to pieces. Even in crowded forests this spruce keeps its lower limbs and looks hale and fresh by the prompt casting of its early ripening cones.
The pale red wood is peculiarly adapted for sounding-boards of musical instruments. It has been used locally in buildings, but of late the wood-pulp mills get most of this timber.
The Engelmann Spruce
P. Engelmanni, Engelm.
The Engelmann spruce is the white spruce of the Rocky Mountains and the Cascade Range of Washington and Oregon, which forms great forests on high mountain slopes from Montana and Idaho to New Mexico and Arizona. Always in damp places, this thin-barked beautiful tree is safest, from fire. The leaves are blue-green, soft and flexible but with sharp callous tips. The cones are about two inches long, their thin scales narrowing to the blunt tips. Each year a crop of seeds is cast and the cones fall. Running fires destroy the seed crop with the standing trees, making renewal of the species impossible in the burnt-over tracts. For this reason, this beautiful spruce tree is oftenest found on the higher altitudes, or where wet ground and banks of snow defend it from its arch enemy. The tree is satisfactory in cultivation, but never equal to the wild-forest specimens. The wood is used locally for building purposes, for fuel and charcoal.
The Blue Spruce
P. Parryana., Sarg.
The blue spruce well known in Eastern lawns as the "Colorado blue spruce," is a crisp-looking, handsome tree, broadly pyramidal, with rigid branches and stout horny-pointed leaves, blue-green to silvery white, exceeding an inch in length. At home on the mountains of Colorado, Utah and Wyoming, it reaches a hundred to a hundred and fifty feet in height and a trunk diameter of three feet, and becomes thin and ragged at maturity. The same fate overtakes the trim little lawn trees, so perfect in color and symmetry for a few years.
P. Sitchensis, Carr.
The tideland spruce is the most important lumber tree in Alaska. It inhabits the coast region from Cape Mendocino, in California, northward; and is abundant on wet, sandy and swampy soil. The conspicuous traits of this tree are its strongly buttressed trunk, one hundred to two hundred feet tall, often greatly swollen at the base; the graceful sweep of its wide low-spreading lower limbs; and the constant play of light and shadows in the tree-top, due to the lustrous sheen on the bright foliage. It is a magnificent tree, one of the largest and most beautiful of the Western conifers, indomitable in that it climbs from the sea-level to altitudes three thousand feet above, and follows the coast farther north than any other conifer.