222 TREES OF MINNESOTA. 



P. parrayana, but makes a larger tree, often growing 100 feet in 

 height. In some nurseries 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; 

 sap wood 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. Easily grown from seeds, which are used in 

 large quantities. The varieties are propagated by grafting on 

 the species. 



Properties of Wood. Light, strong and fine grained. Specific 

 gravity, air dried, 0.47, 



