KEY, BASED UPON LEAVES. 



/. Elevated and persistent 

 g. 4-sided; branchlets 



Pubescent 20. PICEA NIGRA. 



Glabrous 100. PICEA ALBA. 



/ 2 . Flat; branchlets smooth; cones cylindrical 149. PICEA SITCHENSIS. 

 Not elevated nor persistent ; leaves short thick and crowded. 



174. ABIES MAGNIFICA. 

 e 2 . Ridged below, grooved above, nearly equally 4-sided. 



225. ABIES NOBILIS. 



e 2 . Terete 196. PINUS MONOPHYLLA. 



c. Linear, flat and 



d. Conspicuously 2-ranked diverging in two directions, 

 e. Petioled and margin 



f. Obscurely denticulate, obtuse at apex and with persistent bases of 

 petioles (TsuGA) 



Slightly grooved above, cones pedicilate .21. T. CANADENSIS. 



Conspicuously grooved, cones sessile 223. T. HETEROPHYLLA. 



/ 2 . Entire, revolute, acute at apex 144. TAXUS BREVIFOLIA. 



e 2 . Subsessile rigid and sharply bristle-pointed, about 1 inch long and gen- 

 erally tapering from wide base 120. TORREYA TAXIFOLIA. 



1-3 inches long, of more nearly uniform width. 



145. TORREYA CALIFORNICA. 



e 3 . Sessile, entire, keeled below those of the sterile branches 

 /. Narrow-linear 



| in. long, obtusely pointed 22. ABIES BALSAMEA. 



-| in. long, conspicuously emarginate 224. ABIES GRANDIS. 



| in. long, obtuse or acute at apex, rounded above 



173. .ABIES CONCOLOR. 

 p. "Wide-linear, pungent at apex, in. long or less 



143. SEQUOIA SEMPERVIRENS. 

 <? 2 . Somewhat 2-ranked, short-petiolate 

 e. Articulated on a permanent-base and keeled above 



171. TSUGA PATTONIANA. 



e 2 . Breaking away entire and leaving permanent leaf-scars 

 f to 1 in. long ; winter buds -J in. 



150. PSEUDOTSUGA TAXIFOLIA. 



f to 1 in. long ; winter buds J in. 



PSEUDOTSUGA MACROCARPA. 



c 2 . Scale-like or awl-shaped, imbricated and closely appressed 

 d. In 4 ranks and making a conspicuously 

 e. Flat two-edged branchlet; cones with leathery scales and 



4 scales usually fertile 24. THUJA OCCIDENTALS. 



6 scales usually fertile 220. THUJA GIGANTEA. 



e 2 . Flattish but narrower branchlet 141. LIBOCEDRUS DECURRENS. 



c 3 . 4-angled rather than flat branchlet ; cones subglobose, with peltate 



valvate scales 

 /. Maturing the first season, | in. in diameter; leaves entire 



74. CHAM^CYPARIS THYOIDES. 



f* 9 Maturing the second season ; leaves denticulate and 

 g. Obscurely glandular; cones 



i-1 in. long 166. CUPRESSUS GOVENIANA. 



1-1-J in. long 195. CUPRESSUS MACROCARPA. 



gr 2 . Conspicuously glandular-pitted, glaucous 



219. CUPRESSUS MACNABIANA. 

 d. Terenate leaves 



Roundish at apex 166. JUNIPERUS CALIFORNICA. 



More acute at apex 168. JUNIPERUS OCCIDENT ALIS. 



d. 3 Scattered, or spirally arranged, mostly carniate. . .142. SEQUOIA GIGANTEA. 

 c 4 . Laminate and 



d. Elliptical to ovate, about 1 in. long, coriaceous. .201. CEANOTHUS SPINOSUS. 

 d*. Ovate to oblong 

 e. Single-ribbed 

 /. 1-5 in. long, at base 

 ff. Rounded, truncate or slightly heart-shaped, 



