262 UNIVERSITY OF COLORADO STUDIES 



In the Cascade, Selkirk and Rocky Mountain ranges of British Columbia and Alberta, 

 south through the mountain states to New Mexico and Arizona, west to Oregon. It is 

 by far the more abundant of our two species of Picea and is the common tree near timber- 

 line where it forms scrubby mats. In such situations it seldom bears cones. At 10,000 

 to 11,000 feet altitude it reaches its largest size. 



The Engelmann spruce has been planted for ornament in the eastern United States 

 and in Europe. Sometimes it is mistaken for the blue spruce. These two species of 

 Picea are not easily distinguished; however, the size of the cones is a marked feature. 



Genus 3. PSEUDOTSUGA, Douglas Spruce 



Tall conical trees with thick, furrowed bark and strong wood resem 

 bling in quality the best hard pine. Branches generally ascending, the 

 branchlets spreading; general appearance more feathery than true 

 spruce. Leaves linear, flat, narrowed at base to a short leaf-stalk. 

 Cones pendant; usually scattered over the tree; not confined to the 

 upper branches; cone scales persistent; bracts with prominent teeth 

 giving the cone a fringed appearance. Three species of this genus are 

 known; one in Japan, the other two in western North America. 



Pseudotsuga mucronata (Raf.) Sudw. Douglas Spruce. Leaves rather soft, 

 not rigid, flat, channeled above and ridged below, 20 to 35 mm. long, dark yellow-green in 

 color, narrowed to a short stalk; leaf scars not prominent. Cones pendulous, 5 to 10 cm. 

 long, the bracts projecting beyond the scales. Each bract with two lateral teeth and the 

 midrib projected as a rigid awn. 



A tree of handsome conical form, especially when young; reaching the greatest size 

 in the moist forests of Oregon and Washington. Bark on young trees smooth and thin; 

 on older trees very thick and deeply furrowed. Wood hard; light red or yellow; specific 

 gravity 0.5157; largely manufactured into lumber in the Pacific Northwest where it is 

 generally known as "Oregon pine," "Douglas fir" and "red fir." Employed for fuel, 

 railway ties and piles; in Colorado used as Christmas trees. 



British Columbia and Alberta southward through hills and mountains to northern 

 Mexico and western Texas. 



Frequently planted as an ornamental and shade tree in Europe and the eastern United 

 States. Numerous varieties are distinguished in cultivation. 



Genus 4. ABIES, The Firs, Balsams 



Tall conical trees of colder regions and mountain districts. Leaves 

 linear, flat, sessile; grooved above and having a notched apex. On the 

 upper cone-bearing branches the leaves are often curved and thick, with 

 the upper surface convex instead of grooved. Cones erect; purplish- 

 black or yellow, formed of closely overlapping scales; exuding a bal- 



