154 



maintained ; and it is with this object in view that the selection of the 

 first name given has been made. 



Information has been derived from an examination of herbarium and 

 other specimens, as well as from a free use of a large number of forestal 

 and botanical publications ; among them Gray's Manual, Watson's 

 Botany of California, Prof. 0. S. Sargent's Forests of Korth America, 

 Coulter's Manual of Eocky Mountain Botany, together with various 

 Government reports and current botanical and forest literature. In- 

 formation has also been derived from the personal observations and 

 correspondence of Col. E. T. Ensign. 



ARTIFICIAL KEY TO GENERA AND SPECIES. 



I. Leaves without a true stem : 



Needle-sliaped gr scale-like CoNiFEr.s. 



Sword-sliaped, very long, tliick, attached toau uubrauched trunk.. Yuccas. 



II. Leaves with a true stem and a more or less broad blade.. Broad -Leaved Trees. 



III. Leaves none (anomalous) 4'J 



CONIFERS. 



Leaves in clusters: 



2, 3 (not regularly 4), or 5, with a delicate scaly sheath at the base : Pines: 



Leaves 2 in a slieatli : 



1 to 2 inches long ; cones with blunt scales T) 



1 to 3 (mostly 2) inches long ; cones wnth prickle-pointed scales 9 



Leaves 3 (somefimes 2) in a sheath : 



2i- to 3 J inches long ; cones wath delicate pri ckles 8 



3 to 6 inches long; cones with strong prickles - 7 



Leaves 5 in a sheath : 



1 to 1^ inches long ; cones with delicate prickles f) 



li to 2^ incbes long ; cones with blunt scales •> 



li to 2 (exceptionally 2| to 3) inches long 2 



2f to 4 inches long (often 4 in a sheath) ; seeds large, wingless 4 



3 to 4 inches long; seeds small, winged 1 



More than 5, i)roceeding from a bud: Larches : 



14 to 20 leaves in a cluster - • -t^* 



40 to 50 leaves in a cluster '-^^ 



Leaves single: 

 Bristling all around the branches; more or less 4-sided and pointed : Spruces : 



Leaves very stiff, stout, and acutely ^pointed ' 1-^ 



Leaves moderately stiff, rather slender, awl-pointed : 



Cones with margin of scales entire - ^'' 



Cones with margin of scales indented ^^ 



Comb-like, or 2-ranked in arrangement on the branches, flat, blunt, notched, 



or pointed: 

 Leaves rather thin, onslendcr hranches ; cones hanging, scales persistent : 

 Hemlocks, etc. : 



With 3-pointed bracts protruding from under the scales 1'^ 



With no bracts protruding from under the scales : 



Cones i to f of an inch long, downy ' 



Cones 2 to 3 inches long, iwt downy 



