KEY, BASED UPON FLOWERS. 7 



/ 3 . 3-5 in. long ; sheaths elongated ; branchlets 



Rough ; prickle inclined nearly at right angle to the axis of cone 



when closed 75. P. MITIS. 



Smooth ; prickle inclined more towards the apex of the cone. 



123. P. GLABRA. 



/ 3 . l-2 in. long ; sheaths short 98. P. INOPS. 



? 2 . Leaves in 3s and scales of cone thickened at apex and armed with a 

 prickle ; leaves 



3-6 in. long, cone about 2 in. long ; prickles strong 50. P. RIGIDA. 



5-8 in. long ; cone 2-3 in ; prickles weak 121. P. SEROTINA. 



7-10 in. long, stout; cone 3-5 in. long, sessile 147. P. PONDEROSA. 



8-15 in. long ; cone 6-10 in. long 124. P. PALUSTRIS. 



d 3 . Leaves in 5s with very short sheaths ; cones longer than the leaves and 

 with scales not thickened at the ends, unarmed; cones 



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



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



d 4 . Leaves in both 2s and 3s, 7-12 in. long; cone 3-6 in. long, glossy, brown. 



125. P. CUBENSIS. 

 c 2 . Leaves evergreen, scattered (not fascicled) ; cones with thin scales, maturing 



the first year. 

 d. Cones erect, cylindrical, large (3-4 in.); leaves flat, linear (Abies) 



22. A. BALSAMEA. 

 eZ 2 . Cones pendent and 



e. Bracts inconspicuous; cones 

 /. Small, 8 lines or less, scales entire at tip; leaves linear. 



21. TSUGA CANADENSIS. 

 f*. Larger, leaves 4-angled (Picea) 



1-1^ in. long, ovate, scales eroded at tip; branchlets pubescent. 



20. PlCEA NIGRA. 

 2 in. long, cylindrical-ovoid, entire at tip, branchlets smooth. 



100. PlCEAALBA. 



1^-3 in. long, cylindrical, scales elongated and incisely denticulate 



at tip 149. PICEA SITCHENSIS. 



e 2 . Bracts conspicuously exserted, cone 



2-3 in. long 150. PSEUDOTSUGA TAXTFOLTA. 



C 3 . Leaves deciduous, soft, needle-shaped and in fascicles of many each ; cones 

 about 8 lines in length, scales thin (Larix) and with inflected margins. 



23. L. AMERICANA. 

 . Few. 

 c. Imbricated, without bracts and each bearing two erect ovules; flowers 



Monoecious, scales thinnish and 8-12 (Thuya) 24. T. OCCIDENTALIS. 



Dioecious, scales fleshy and consolidated, making a dark blue berry-like 



fruit . . 25. JUNIPERUS VIRGTNIANA. 



c 2 . Valvate, thick, and only one pair fertile 141. LIBOCEDRUS DECURRENS. 



C 3 . Peltate, with edges joined, cones 

 d. Subglobose, short, 



in. in diameter, scales usually 6 (Chammcyparis) ... .74. C. THYOIDES. 



1 in or less in diameter; scales 15-20 119. TAXODIUM DISTICHUM. 



dP. Ovoid-oblong, scales diverging at right angles to axis and rhornboidal at 

 apex; cones 



2-3 in. long 142. SEQUOIA GIGANTEA. 



1 in. or less 143. SEQUOIA SEMPERVIRENS. 



3 . Differentiated into a fleshy covering or cup, with single erect seed. 

 c. With fleshy covering (drupe-like), sessile and 



1 in. or slightly more long 120. TORREYA TAXIFOLIA. 



About l in. long 145. TORREYA CALIFORNICA. 



c 2 . Subtended by a red fleshy cup 144. TAXUS BREVIFOLIA. 



