YELLOWSTONE NATIONAL PARK 



(green) (green) 



19 



SHKUBS. 



Willow (Salix). Willows, as well as a number of 

 other plants that reach tree size at lower altitudes, 

 must be classified as shrubs in Yellowstone Park. 

 Even the few willow trees behind the hotel at Mam- 

 moth Hot Springs are not native, but were brought 

 in and planted. The shrubby willows are to be found 

 in great abundance near water-courses and lakes all 

 over the Park. There are a number of species here, 

 with leaves ranging from the very long and narrow, 

 as in the long-leaf willow, to the broad and blunt, as 

 in the peach-leaved species; but for practical purpos- 

 es they may be lumped together under one head. 



Birch {Betula). The birch found in the Park is 

 a tall shrub, quite abundant along the water-courses 

 and in little, moist valleys on the hillsides, particu- 

 larly at the lower elevations. It commonly attains a 

 height of fifteen or twenty feet. Its most striking 

 feature is the glossy, dark-red bark, thickly set with 

 horizontal white markings. The leaves are small and 

 rounded, and finely toothed around the margins. The 

 fruiting body is cylindrical, comparatively long and 

 narrow. 



