KEY, BASED UPON FRUIT. 15 



h. Thin at tip and unarmed; cones subcylindric and 



4-6 in. long 49. P. STROBUS. 



5-11 in. long 221 P. MONTICOLA. 



12-18 in. long 146. P. LAMBERTIANA. 



/ir- 2 . Thickened at tip and 

 i. Armed with a recurved prickle. 



7. 1-3 in. long, cylindric ovoid, oblique. 148. P. CONTORTA. 



J 2 . 3-6 in. long, glossy-brown, 

 k. Elongated conical, separating from the tree by a fracture 



Within the peduncle 125. P. CUBENSIS. 



Within the base of cone 147. P. PONDEROSA. 



7c 2 . Broad-ovoid 197. P. TORREYANA. 



h\ Subcylindrical, 3^-5 in. long, with very weak prickle. 



246. P. BALFOURIANA. 



/. 6-10. in. long 124. P. PALUSTRIS. 

 Unarmed, cones about 2 in. in length, seeds 



J. Winged, about in. long 19. P. RESINOSA. 



j*. Wingless; leaves. 

 k. In fives; cones. 



li-3 in. long , 244. P. ALBICAULIS. 



3-10 in. long 243. P. FLEXILIS. 



& 2 . In fours 245. P. QUADRIFOLIA. 



k 3 . Single 196. P. MONOPHYLLA. 



</ 5 . Lateral and scales thickened at tip, cones 

 h. Slightly or not at all oblique 

 i. Ovoid-oblong; leaves 3-5 in. long; scales armed with a weak prickle 



directed 

 At about right angles from the axis of the closed cone. 



75. P. MITIS. 



Forward, at about 45 or less from the axis 123. P. GLABRA. 



i 9 . Ovoid-pyramidal. 

 j. Prickles strong; cones 2 in. or 



Rather less in length ; leaves l|-3 in. long ; branchlets purple. 



89 P. INOPS. 



Rather more ; leaves 3-5 in. long 50. P. RIGIDA. 



j 2 . Prickles weak; cones 2-3 in. long, and 



Wide-pyramidal; leaves in 3's 121. P. SEROTINA. 



Narrow-pyramidal; leaves in 2's. , 122. P. CLAUSA. 



/l 2 . Markedly oblique 



2-in. or less in length, scales unarmed 99. P. BANKSIANA. 



2-3 in. long, scales armed with strong prickles. .170. P. MURICATA. 

 3-5 in. long, outer scales very gibbous; oblique. 



Ovoid, prickles minute and weak 190. P. RADIATA. 



Cyllindrical ovoid, prickles stouter 222 P. ATTENUATA 



4-8 in. long; scales very strongly armed 198. P. SABINIANA. 



10-15 in. long, armed with very" large, strong prickles. 



169. P. COULTERI. 



/ 2 . Maturing the first season the autumn after blossoming. 

 g. Ovoid or oblong, in. long, pendent ; bracts inconspicuous; scales per- 



pistent on the axis, thin and with eroded tip 20. PICEA NIGRA. 



gr 2 . Ovoid, pendent; scales thin and entire at tip. 



Pedunculate, f-f- in. long; cone scales orbicular oblong bracts 



truncate 21. TSUGA CANADENSIS. 



Sessile, f-1 in. long; cone-scales oblong; bracts cuspidate. 



223 TSUGA HETEROPHYLLA. 

 gr 2 . Ovoid, small (8 lines or less), pendent, scales rounded and entire at tip. 



21. TSUGA CANADENSIS. 

 f/ 3 . Subcylindrical 



/i. Erect ; scales deciduous from the persistent axis (Abies); bracts 

 ?*. Shorter than cone- scales; leaves with resin ducts 

 J. Within the parenchyma 



Cones 2-4 in. long, purple 22. A. BALSAMEA. 



j*. Close to epidermis of lower side; cones 



