THE FOREST TREES. 



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The western hemlock (Tsuga heterophylla (Raf.) Sarg.) : This tree, 

 commonly known as the hemlock, differs from its eastern relative (Tsuga 

 canadensis (Linn.) Carr.) in having slightly larger cones with scales 

 longer than broad. In the eastern species the scales are nearly as broad 

 as long, and the cones have a stalk, whereas the cones of the western 

 species are sessile. The leaves are rounded at the apex, flat, dark green 

 above, white below, and have short leaf stalks, or petioles. The bark on 

 full-grown trees is about one and a quarter inches thick and has rather 



Fig. 13. Leaves and cones of the western Hemlock. Photo by M.J. E. 



broad flat connected ridges with brownish scales. The tree, like the 

 giant arborvitae, is very tolerant of shade. It is even more restricted in 

 Montana than the giant arborvitae, and like it reaches its best develop- 

 ment on the Pacific coast. (Fig. 13.) 



The young trees of the Douglas spruce, lowland fir, Engelmann spruce 

 and Alpine fir look alike to the uninitiated. The last named species is 

 not often associated with the others, and hence is not so likely to be mis- 

 taken for it. The base of the leaf of the Engelmann spruce is woody, 

 and remains attached to the stem after the leaf is shed, thus leaving 

 pegliKe projections on the stem. The spruce can be easily distinguished 



