a b" c 3 d e 30 



f 2 Blue-green; cones %-!% in., with incurved stalks; cones with erose mar- 

 gined scales BLACK SPRUCE (Picea Marinana ) . 



e- Branchlets glabrous; cones oblong-cylindrical; about 



f 2 in. long, with nearly orbicular scales, truncate and entire at apex. 



WHITE SPRUCE (Picea Canadensis). 

 f- 2%-4 in. long, with rhomboidal, flexuose scales, narrow erose-dentate and 



elongated at apex BLUE SPRUCE (P. Parryana) , 



d 2 Leaves in fascicles, 



e Evergreen, quite stiff and in fascicles of 



f 2 each, a membranaceous sheath inclosing the base of each fascicle, about 



g 1 in. long, sheaths very short JACK PINE (P. divaricata) . 



g 2 l%-2% in. long; sheaths % in. or less; branchlets smooth and purple. 



JERSEY PINE (P. Virginiana) . 

 gs 3-5 in. long; branchlets rough. 



h Cones iy 2 -2 in., narrow ovoid, scales armed with weak prickles. 



YELLOW PINE (P. echinata). 



h 2 Cones 3-4 in., broad-ovoid, scales armed with very thick stout prickles. 



TABLE-MOUNTAIN PINE (P. pungens). 

 g 4 5-6 in. long, thick and with smooth-bossed cones. 



RED PINE (P. resinosa). 



f 2 3 each and 3-6 in. long; cones 1^-3 in PITCH PINE (P. rigida) . 



g'> 5-8 in. long; cones 



h 2-3 in., globular-ovoid, persisting closed on the branches for some years. 



POND PINE (P. serotina). 



