162 



at altitudes of 2,500 to 3,500 feet. (From British Oolniobia and north- 

 ward the range of this species extends along the northern boundary of 

 the United States to Maine and northward.) Extensively used for lum- 

 ber, and as such not distinguished from that of the Blact Spruce (Picea 

 nlgra^ Link.), with which it is much associated in its northern distribu- 

 tion. 



Desvriniion. — Leaves J to f of an inch long, stiff, erect, or curred. Cones nearly 

 sessile or on stems jV to \ of an inch long; 1 to 2 inches long, cylindrical or oblong ; 

 scales with entire margin. 



11. — Engelm ANN'S SrRUCE. White Spruce, Red Spruce. (Picea 



Engdm anni, En gel m . ) 



The most valuable timber tree in the Eocky Mountain region, form- 

 ing large forests. It ranges from New Mexico to Montana (westward 

 and north of the United States boundary), usually seeking dry gravelly 

 ridges between 5,000 and 11,500 feet; in Colorado, where it attains its 

 greatest size, occurring at elevations from 9,000 feet up to the timber 

 line 5 100 to 130 feet in height, and over 3 feet in diameter; but attiie 

 highest limit of growth only a prostrate shrub. The wood is tough, 

 strong, and elastic. Nearly all the rough and dressed lumber used in 

 the Rocky Mountain region is of this spruce. It is best adapted toinsido 

 work, but when well seasoned aud protected with paint can be used 

 outside; is said to warp and crack too much for good shingles. The 

 wood is also largely used for fuel aud charcoal. Bark valuable for tau- 

 uing. 



The spruce forests in the Rocky Mountain region are very important 

 in holding the snow and preserving a How of water in the streams. 

 Thus the snow is often retained as late as the 1st of August; and the 

 growing season for these trees does not average more than two months. 



Description. — Leaves ^ to y'o of an inch long, strongly keeled, aud awl-pointed. 

 Cones ovate-cylindrical; 1| to *2f iuclies long, and f to 1 inch in diameter; on stcn)s 

 ^to I of an inch long; reddish brown when mature ; scales thin, horny, rhonihoichil, 

 with truncate tip, which is entire, with two to three small teeth, or rounded. 

 Branches mostly short and small. Bark scaly, grayish, or reddish-purple. 



12. — Blue Spruce. White Spruce. "Balsam." (Picea pungens^ 



Engelm.) 



A local and somewhat rare tree occurring in central Rocky Mount 

 ain region — Wyoming, Colorado, and Utah — between G,000 aud 9,000 

 feet. It prefers a damp soil, and grows rapidly in such situations, at 

 taining a height of over 100 feet, with a diameter of 3 feet or more. The 

 wood is light, soft, weak, and probably of little value. The trunks 

 taper too rapidly to be cut into lumber to advantage. 



Bescription. — Leaves ^ to of an inch long, rigid, 4 angled, needle-pointed. Cones 

 light reddish-brown, 3^- to 4 (often I")) inciios long, by IMiiclies iu diameter; scales 

 very thin, rhomboidaL truncated, with wavy, irregular, or entire margin. Bark gray- 



