1 8 WEST-AMERICAN 



axis, in spiral lines or coils, from below upward, and 

 from base to apex. Cones requiring afc-leaek two sea- 

 sons to mature. 



Separated by general characters into Three 

 Tribes: 



Tribe One -ABIETINE/E 

 THE NORTHERN PITCH-TREES. 



Very resinous trees; fruit a woody or leathery 

 cone, or bur, of spirally overlapping scales on an 

 elongated axis, each scale bearing two usually winged 

 seeds. Flow r ers monoecious, i. e., on separate branch- 

 lets of the same tree. All natives of the Northern 

 Hemisphere. 



Separated by foliage-association into Two large 

 Sub-Tribes: 



Sub Tribe One -FASCICUL/E 

 FASCICLE-LEAVED PITCH-TREES. 



Trees with the conspicuous secondary leaves in fas- 

 cicles or bundles of 2 to 5 each, or in elongated tufts 

 of many leaves in each. 



Separated by foliage-duration into Two Classes: 



