By a tree is meant any woody plant 

 with well-defined central stem or trunk 

 and a height of at least 15 feet. All 

 woody plants which retain their lateral 

 shoots so that their branches are formed 

 near the ground and are less than 15 

 feet high are properly called shrubs and 

 are not considered in this book. The 

 reader will do well to bear this in mind. 

 Arbitrarily the author has considered as 

 mountain trees only those occurring at 

 an elevation above 3500 feet. 



In dealing with the pines, I have ar- 

 ranged them in the order of the number 

 of needles in a bundle, an easy classifi- 

 cation which will be helpful to many. 

 Since each species bears in its bark, leaf, 

 and cone the most prominent distin- 

 guishing characters, synoptic descrip- 

 tions of these are given at the beginning 

 of each sketch. 



The valuable assistance of Mr. 

 Charles F. Saunders and Mr. S. B. Par- 



6 



