Field Manual 



'2. Dwarf branches mostly with 2 foliage leaves; some 

 of them may be with 3. 5. 



3. Leaves 6-10 in. lonji^: carpellate cone oblong-conic 

 or ovoid. 4. 



3. Leaves 3-5 in. long ; carpellate cones ovoid. P. rigidu. 



i. (^Id sheaths of the dwarf branches 5-1 in. long; leaves 

 not glaucous ; carpellate cones oblong-conic. P. 

 tarda. 



[. Old sheaths about i in. long; leaves glaucous; car- 

 pellate cones ovoid. P. scrotina. 



■ ). Twigs glaucous ; resin-ducts parenchymatous ; car- 

 pellate cones li-3 in. long; ovuliferous scales with 

 a prickle or small spine. 6. 



•J. Twigs not glaucous. 7. 



• !. Leaves slender. 2.]-') in. long; buds not very resin- 

 ous ; prickles of the ovuliferous scales short and 

 small. P. cchinata. 



ti. Leaves stout. \\-2.l in. long; buds very resinous; 

 prickles of the ovuliferous scales long and stout. 

 P. inrginiana. 



7. Leaves 1-4 in. long, grayish-green or light green ; 

 ovuliferous scales without or wij;h a small prickle, 

 or with a thick point or spine. 0. 



7. Leaves 4-ti in. long, dark-green; ovuliferous scale 

 without a spine or prickle, or sometinies with a 

 very small prickle. ^. 



S. Foliage lustrous, resin ducts peripheral ; carpellate 

 cones terminal or subterminal, oval-conic ; ovulif- 

 erous scales pointless when mature. P. rcsinosa. 



S. P'oliage dull ; resin ducts parenchymatous ; carpellate 

 cones lateral, ovoid-conic; ovuliferous scale with 

 a small prickle. P. Jaricio. 



'.'. Leaves 2^-4 in. long, grayish-green; twigs orange or 

 brown ; resin ducts parenchymatous ; carpellate 

 cones ovoid; 3-5 in. long. P. pimgens. 



!•. Leaves l-2\ in. long. 10. 



10. Leaves U-2J in. long, grayish-green; twigs dull 

 greenish-yellow or greenish-brown; resin ducts 

 peripheral ; carpellate cones ovate-conic. 2-3 in 

 long. P. silresfris. 



