ENUMERATION OF CONIFERS 271 



E. Color of branchlets brown: leaves dark green: cone- 

 scales rounded and entire at apex, stiff : cones 2-3 

 inches long. 

 F. All leaves pointed, %-% inch long, spreading 

 (see also 10, P. Abies). 

 G. Leading shoot glabrous or nearly so: leaves with 



more numerous stomata above than beneath. 14. P. Koyamai 

 GG. Leading shoot and other branchlets pubescent: 



leaves equally stomatiferous on all four sides . . 1 1 . P. oborata 

 FF. All leaves obtuse, very lustrous, ^-3^ inch long, 



more or less appressed 12. P. orienialis 



EE. Color of branchlets yellowish to grayish. 



F. Length of leaves J^^-% inch: cone with obovate, 

 stiff entu-e scales. 

 G. Cone 3-5 inches long: leaves slender, slightly 



pungent, straight 9. P. asperata 



GG. Cone 23-4-3 inches long: leaves stout, usually 



curved, not pungent 13. P. Meyeri 



FF. Length of leaves ^/i-\ inch, often glaucous: cone to 



3 inches long, with rhombic, flexible erose scales. 20. P. Engelmanni 

 DD. Terminal winter-buds with a ring of conspicuous subu- 

 late scales at base: leaves often with fewer stomata 

 beneath than above: cone l}<t-2}<4 inches long. 



E. Pubescence of branchlets non-glandular 16. P. Glehnii 



EE. Pubescence of branchlets glandular. 



F. Cones green before matiu-ity, falling soon after 



maturity: leaves lustrous green 17. P. rubra 



FF. Cones persisting for several years, purple before 



maturity: leaves glaucous or bluish-green 18. P. mariana 



BB. Leaf more or less compressed, in cross-section broader than 

 high, with at least twice as manv stomata above as be- 

 neath (see also 16, P. Glehnii). 

 c. Stomata of leaves about twice as many above as beneath: 

 leaves slightly compressed. 

 D. Branchlets at least partly glabrous: bud-scales not 

 acuminate. 

 E. Length of leaves }4-H inch: leading branchlets gla- 

 brous or nearly so; the lateral ones glandular- 

 pubescent 14. P. Koyamai 



EE. Length of leaves %-l inch: the leading branchlets 



pubescent, the lateral ones glabrous 15. P. bicolor 



DD. Branchlets pubescent: lower bud-scales long-acuminate 



and keeled: cone with thin denticulate scales 22. P. montigena 



cc. Stomata of leaves of only 1 or 2 usually broken rows be- 

 neath: leaves distinctly compressed, with conspicuous 

 bands above: cone with thin denticulate scales. 

 D. Apex of leaves acute or mucronate: cone brown or 



slightly purplish, with nearly rounded scales 23. P. Balfouriana 



DD. Apex of leaves obtuse or bluntly mucronate: cone purple, 



their scales attenuate above the middle and wavy . . . .24. P. purpurea 

 AA. Leaves flattened with white bands above, without stomata be- 

 neath or occasionally only with a broken row. 



