I20 UNIVERSITY OF COLORADO STUDIES 



Along the mountain streams of eastern Colorado, west to Utah and north to the 

 Wind River Mountains of Wyoming, occurring singly or in small groves. 



Much cultivated for ornament in this country and in Europe. There are numer- 

 ous horticultural varieties propagated by grafting. 



Picea engelmanni (Parry) Engelm. Engelmann Spruce 



Rydberg, Flora Colo. 8; Coulter, Manual 431; Sargent, Manual Trees of 

 N.A. 43; Nelson, Key to Rocky Mountain Flora 6. 



Leaves ridged above and below so that they are rather four-sided; awl pointed; 

 not so stiff as those of 'the blue spruce. Leaves at first covered with a bluish or 

 silvery bloom which disappears later; slender, 25 to 30 mm. long on the ordinary 

 branches but shorter on cone-bearing twigs; stomata in 3 to 5 rows on each of the 

 four surfaces of the leaf. Cones 3 to 5 cm. long, the cone scales truncate or acute 

 at tip, sometimes toothed. 



A large conical tree of the higher foothills and mountains; near timber limit a 

 straggling, prostrate shrub. Bark thin, broken into large, thin, loose scales. Wood 

 light, soft, close grained, not strong; specific gravity 0.3449. Frequently used for 

 lumber and for making charcoal. The bark has been employed for tanning leather. 

 In some localities the Engelmann spruce has been largely cut for railway ties and to 

 some extent for telegraph and telephone poles. It should be valuable for wood 

 pulp. 



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 com- 

 mon tree near timber line where it forms scrubby mats. In such situations it seldom 

 bears cones. 



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 usually 

 a marked feature. In addition the number of rows of stomata on the leaves and 

 the character of the bark should be noted. The leaves of the blue spruce are dis- 

 tinctly stiffer than those of the Engelmann spruce. 



Genus PSEUDOTSUGA, Douglas Spruce 



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

 bHng in quality that of the best hard pines. Branches horizontal or ascending with 

 a somewhat more feathery appearance than the true spruces. Leaves linear, flat; 

 with a short leaf-stalk; the face of the leaf grooved above and with a prominent 

 midrib below. Stomata (pores) on the under surface. Flowers solitary, appearing 

 early in spring; the staminate scattered along the branches, small, oblong-cylin- 

 drical; the carpellate reddish-purple, borne near the tips of upper branches, easily 



