229 TREES OF MINNESOTA. 
P. parrayana, but makes a larger tree, often growing 100 feet in 
height. In somenurseries it is customary to tell the Colorado Blue 
Spruce from the Engelmann Spruce by grasping the top of the 
young tree with the hand, when, if it pricks only a little, the tree 
is set down as Engelmann Spruce, while if the pricking is unen- 
durable, it is called Colorado Blue Spruce. This method of 
determining the species generally gives correct results, but a 
certain way is to examine the bark of the new growth between 
the needles which, if slightly downy, indicates the Engelmann 
Spruce, and if smooth and shining, the Colorado Blue Spruce. 
Distribution —Northern New Mexico, Arizona, Colorado, 
northward to British Columbia, in the mountains at high eleva- 
tions. 
Propagation.—By seeds. 
Properties of Wood.—Very light, soft, weak, very close straight 
grained, compact, satiny; color, pale yellow, tinged with red; 
sapwood hardly distinguishable. Specific gravity, 0.3449; weight 
of a cubic foot, 21.49 pounds. 
Uses——The Engelmann Spruce is a valuable ornamental and 
timber tree, resembling the Blue Spruce, but it has been tried to 
only a limited extent. It is the most valuable timber tree of the 
central Rocky Mountain region, where it forms extensive for- 
ests. In Colorado it is manufactured into lumber, and is largely 
used for fuel, charcoal, etc. The bark is rich in tannin, and in 
Utah is sometimes used for tanning leather. 
Picea excelsa. Norway Spruce. 
Leaves long, deep green in color, falling during the fifth sea- 
son. Cones cylindrical, large, five to seven inches long, light 
colored, often very conspicuous in the tops of the trees. A fine, 
large conical tree, with stout branches and generally pendulous 
branchlets. There are numerous horticultural varieties, some of 
the dwarf forms growing only three to five feet high. 
Distribution.—Native of Northern Europe and Asia. 
Propagation.—Ejasily grown from seeds, which are used in 
large quantities. The varieties are propagated by grafting on 
the species. 
Propertics of W'ood.—Light, strong and fine grained. Specific 
gravity, air dried, 0.47. 
