UNITED STATES DEPARTMENT OF AGRICULTURE 

 BULLETIN No. 327 



Contribution from the Forest Service 

 HENRY S. GRAVES, Forester 



Washington, D. C. 



PROFESSIONAL PAPER 



February 19, 1916 



THE SPRUCE AND BALSAM FIR TREES 



OF THE ROCKY MOUNTAIN 



REGION 



By 

 GEORGE B. SUDWORTH, Dendrologist 



CONTENTS 



Scope of the Bulletin 1 



Generic Characteristics of Spruces . . 2 

 Black Spruce Picea mariana (Mill.) 



B.,S., &P 3 



White Spruce Picea canadensis 



(Mill.) B., S., & P 6 



Engelmann Spruce Picea engel- 



manni Engelmann 10 



Blue Spruce — "Colorado Blue Spruce" 

 Picea parryana (Andre) Gard- 

 ners' Chronicle 14 



Generic Characteristics of Balsam Firs. . 17 

 Balsam Fir Abies balsamea (Linn.) 

 Miller 20 



Page 

 Generic Characteristics of Balsam Firs- 

 continued 

 Alpine Fir Abies lasiocarpa (Hook.) 



Nuttall 24 



Cork Fir Abies arizonica Merriam 27 

 Grand Fir— "White Fir" Abies 



grandis Lindle y 29 



White Fir Abies concolor (Gord.) 



Parry 33 



Shasta Red Fir Abies magnified 



shastensis Lemmon 38 



Key to Genera 42 



Key to Picea 42 



Key to Abies 43 



WASHINGTON 



GOVERNMENT PRINTING OFFICE 



1916 



