THE FOREST TREKS. 



227 



the lower branches are usually short, stout, roundish in cross section, 

 sharp pointed and a dark blue-green in color. They persist about eight 

 years. The cones (Fig. 15) are about two inches long, sessile or very short 

 stalked. At first they are horizontal but later drop. They mature at the end 

 of the first season. The bark is thin and broken into large flaky scales. 

 The tree on account of its thin bark, is easily destroyed by fire. It toler- 

 ates shade fairly well. It reaches its best development in moist situa- 

 tions, in swamps, along streams, and on moist hillsides. Outside of Mon- 

 tana it has a wide range in the western part of the United States and 

 British America, usually in rather high altitudes. 



Fig. 15. Leaves and cones of Engelmann's spruce. Photo by M.J. E. 



The Douglas spruce (Pseudotsuga taxifolia (Lam.) Brit.) (Pseudo- 

 tsuga Douglassii Car.): This tree, also known as the red fir, is neither 

 spruce nor a fir, the name Picea being reserved for the former, and Abies 

 for the latter. The word Pseudotsuga means literally "false hemlock," 

 but the name has little or no significance. 



The leaves of this tree have already been described. They remain 

 on the tree about eight years . The cones, (Fig. 14) as already stated, 

 are easily characterized by the fact that the bracts are longer than the 

 scales. They vary in size from two to four inches. The bark (Fig. 7) 

 of the tree varies greatly as the tree ages. In the older trees it is com- 

 posed of large, broad, irregularly connected ridges. The bark is very 

 thick at the base, usually from six to twelve inches, and even in excep- 



