CONIFERS, 



SILVA OF NORTH AMERICA. 



27 



CONSPECTUS OF THE NORTH AMERICAN SPECIES 



3. P. Canadensis. 



EupiCEA. Leaves tetragonal, stomatiferous on the four sides. 

 Cone-scales rounded at the apex. 



Cone-scales stiff and ridged at maturity ; branchlets pubescent. 



Cones ovate on strongly incurved stalks, persistent for many years, their scales arose or 



dentate ; leaves blue-green • . - • 1. P. Maeiana. 



Cones ovate-oblong, short-stalked, early deciduous, their scales entire or obscurely 



denticulate ; leaves dark yellow-green 2. P. EUBENS. 



Cone-scales soft and flexible at maturity ; branchlets glabrous. 



Cones oblong-cylindrical, slender, their scales entire ; leaves blue-green 



Cone-scales usually oblong or rhomboidal ; leaves blue-green. 

 Branchlets pubescent ; leaves soft and flexible. 



Cones oblong-cylindrical, or oval, their scales narrowed to a truncate or acute apes, or 



occasionally obovate and rounded, erose-dentate or entire 4. P. Engelmanni. 



Branchlets glabrous ; leaves rigid, spinescent. 



Cones oblong-cylindrical, their scales rhomboidal, flexuose, rounded or truncate at the 



erose apex 6. P. Parktana. 



Omokika. Leaves flattened, usually stomatiferous only on the upper surface. 

 Cone-scales rounded, entire ; branchlets pubescent. 



Cones oblong-cylindrical, slender ; leaves obtuse, stomatiferous only on the upper surface 6. P. BrewebiANA. 

 Cone-scales oblong-oval, rounded and denticulate above the middle ; branchlets glabrous. 



Cones cylindrical-oval; leaves acute op acuminate, stomatiferous on the upper and 



occasionally also on the lower surface 7. P. Sitchensis. 



•i\ 



