HOUGH'S AMERICAN WOODS. 



e*. Five each, 



/. 1-1 in. long ; cones 3|-5 in. long 246. P. BALFOUEIANA. 



/*. l|-3 in. long ; cones from 



1^-3 in. long 244. P. ALBICAULIS. 



3-10 in long 243. P. FLEXILIS. 



/ 3 . 3-5 in. long 



Very slender; cones 4-6 in. long 49. P. STKOBUS. 



Thicker; cones 5-11 in. long 221. P. MONTICOLA. 



Stout; cones 10-18 in. long 146. P. LAMBERTIANA. 



/ 4 . 9-13 in. long; cone-scales thickened at apex and furnished with strong 



prickle 197. P. TORREYANA. 



d 2 . Not in fascicles (scattered) 

 e. Ridged above and below and base 

 f. Elevated and persistent 

 g. 4 sided; branchlets 

 h. Pubescent ; leaves 



- in. long, quite stiff 20. PlCEA NIGRA. 



1-1 in. long, quite flexible 247. PICEA ENGELMANNI. 



h?. 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 8 . Ridged below, grooved above, nearly equally 4-sided ; bracts of cones 



Included, about half as long as scale 249. ABIES AMABILIS. 



Exserted and strongly reflexed 225. ABIES NOBILIS. 



e 8 . Terete 196. PINUS MONOPHYLLA. 



c 5 . Linear, flat and 



d. Conspicuously 2-ranked diverging in two directions, 

 e. Petioled and margin 



/. 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, widest at base and with broad shallow grooves beneath 



120. TORRE YA TAXIFOLIA. 

 /*. 1-3 inches long, more uniform in width. 

 White-stomatose beneath. 



248. ABIES VENUSTA. 

 With deep narrow grooves beneath. 



145. TORREYA CALIFORNICA. 



e 8 . 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. 

 /*. Wide-linear, pungent at apex, in. long or less 



143. SEQUOIA SEMPERVIRENS. 

 c? 5 . Somewhat 2-ranked, short- petiolate 

 e. Articulated on a permanent-base and keeled above 



171. TSUGA PATTONIANA. 



c s . Breaking away entire and leaving permanent leaf-scars 

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



150. PSEUDOTSUGA TAXIFOLIA. 



f to U in. long 5 winter buds -| in. 



171. PSEUDOTSUGA MACROCARPA. 



c 3 . 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*. Flattish but narrower branchlet 141. LIBOCEDRUS DECURRENS. 



