50 p o 1 e l s i a 



Of the plants on the foothills and 

 in sub-alpine regions, many are well 

 known farther east at ordinary altitudes, 

 although not occurring in the plains 

 region of Colorado. Mention may be 

 made of Dasiphora fruticosa, Pulsatilla 

 kirsutissinza, Arctostaphylos uva ursi, 

 Chamancerion angustifolium, Pop ulus 

 tremuloides, Pyrola spp. Throughout 

 the foothills the dominant plants among 

 trees are conifers ; in fact the other 

 trees are so few that they may almost 

 be left out of account so far as the 

 general appearance of the landscape is 

 concerned. The quaking asps in some 

 places, however, are in sufficient num- 

 bers to make an appreciable showing. 



Perhaps the one feature of the 

 vegetation to which special attention 

 should be called is the natural mass- 

 ing of plants of a species in large 

 areas. Instead of a few plants of one 



