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Key to Species — Part 4

A. Leaves distinctly 4-angled.

B. Branchlets pubescent.

C. Leaves blue-green, short.

D. Cones ovate, 1/2 to 1 1/2 inches long, persistent, foliage spiny. (Picea Mariana) BLACK SPRUCE

DD. Cones oblong, 1 to 3 inches long, deciduous; foliage soft and flexible.

(Picea Engelmanni) ENGELMANN SPRUCE

CC. Leaves yellow-green, spiny, cones 1 to 2 1/2 inches long, early deciduous. (Picea rubens) RED SPRUCE

BB. Branchlets smooth; leaves spiny, incurving, blue-green.

C. Cones slender; scales entire, flexible, blunt; leaves strong smelling, 1/2 to 3/4 inch long. (Picea Canadensis) WHITE SPRUCE

CC. Cones stout, scales, ridged, pointed; leaves 1/2 to 1 1/4 inches long. (Picea Parryana) COLORADO BLUE SPRUCE

AA. Leaves more or less flattened; cones 2 to 5 inches long.

B. Branchlets pubescent, pendulous; leaves blunt; cone scales entire, rounded. (Picea Breweriana) WEEPING SPRUCE

BB. Branchlets smooth, erect; leaves pointed;, cone scales toothed, pointed. (Picea Sitchensis) SITKA SPRUCE

The genus Picea includes some of the most useful as well as ornamental of the conifers. There are eighteen species, seven of them American, distributed over the Northern Heimsphere. The Norway spruce (P. excelsa, Link.) is the commonest species in cultivation. It is the familiar spruce of dooryards, growing to great size in this country, and evidently more comfortable in domestication than our native species. The long cones hang on the topmost branches, and the lower limbs droop to the ground. It is planted for windbreaks, hedges and shelter belts, often with white pine. The species is strongly recommended for plantations of trees for timber.

The Caucasian Spruce (P. orientalis, Carr.), graceful and slow of growth, with lustrous, dark-green foliage, is well adapted to small gardens. It retains its lower limbs until quite old. Two or three Japanese species have been introduced.

Black Spruce (Picea Mariana, B. S. & P.)--Pyramidal evergreen, with short, drooping branches, usually 30 to 40 feet high, occasionally 80 feet high. Twigs downy. Bark thin, scaly, brownish grey. Wood light, weak, soft, yellow. Buds brownish red, downy, ovate. Leaves blue-green, with pale bloom above, linear, sharp, stiff, 1/4 to 3/4 inch long, set around twig. Flowers cone-like, monoecious, solitary, axillary. Fruit oval cones, 1/2 to 1 1/2 inches long, pendant, persistent for many years; scales thin, entire. Preferred habitat, dry lowlands, rocky slopes and bogs. Distribution, Labrador to Alaska; south to Wisconsin, Pennsylvania and northern Virginia. Uses: Locally as lumber and fuel. Wood made into paper pulp. Resin used as chewing gum. Sap made into beer.

The least of all spruce cones grow on the black spruce trees, and the tree is burdened with the empty husks of twenty or more crops before it lets the oldest ones drop. It is a peculiar habit, and gives the tree an unkempt, dingy appearance that the grey bark intensifies. The habit of the tree is ragged and uneven, and the foliage dull bluish grey. Altogether it is not to be wondered at that the black spruce is ignored by planters. The tree has always proved short lived in gardens.

The vast forests of this timber will be converted into paper. Wherever spruce timber grows to-day there are fortunes awaiting the owners. This wood that lumbermen reject exactly suits the pulp man's needs. Thousands of acres are consumed every year. Black as its name is, the wood is almost white, and the paper needs little or no bleaching.

The Engelmann Spruce (P. Engelmanni, Engelm.) is the white spruce of the Rocky Mountains and the Cascade range in Washington and Oregon. It crowns the lower and higher peaks, climbing to altitudes between one and two miles above the level of the sea. In the rocky sides of glacier-polished ravines these hardy trees find foothold, and set their spires like serried ranks of spearsmen to cover the bare cliffs. Snow loads them down for many months of the year; they can survive that, but their destruction comes when a fire sweeps over them, killing all it touches, for the cambium of these trees is protected by a very thin bark. The seeds and seedlings go. There is no reproduction of forests thus destroyed. They give way to the lodge-pole pine and other more fortunate species.

The Engelmann spruce is planted in the Eastern States, where it thrives. The disagreeable odour of the leaves counts against it. But the finest trees cannot be seen unless a journey be taken by the northernmost route to the Canadian Rocky Mountains, where snows protect the forests from devastating fires, and these spruce trees grow to 150 feet high, with diameters of 4 or 5 feet. In late spring the blue-green foliage is jewelled with the flowers, purple and scarlet. In autumn the showy cones, with their shining brown, pointed scales hang out on the highest twigs and fling down their black, winged seeds. Here is a vastly different tree from the tame little seedling that began life in a nursery row.