60 



TREES OF NORTH AMERICA 



longer rounded or obtusely pointed (not acute) bright yellow bracts which sometimes 

 cover nearly half their scales. 



9. Abies venusta K. Koch. Silver Fir. 

 Abies bracteata D. Don. 



Leaves thin, flat, rigid, linear or linear-lanceolate, gradually or abruptly narrowed 

 toward the base, often falcate, especially on fertile branches, acuminate, with long slender 

 callous tips, dark yellow-green, lustrous and slightly rounded on the upper surface marked 

 below the middle with an obscure groove, silvery white or on old leaves pale on the lower 

 surface, with bands of 8-10 rows of stomata between the broad midrib and the thickened 

 strongly revolute margins, 2-ranked from the conspicuous twist near their base and spread- 

 ing at nearly right angles to the branch, or pointing forward on upper fertile branches, 

 l|'-2j' long, on leading shoots standing out at almost right angles, rounded on the upper 

 surface, more or less incurved above the middle, l|'-lf' long, about |' wide. Flowers: 

 male produced in great numbers near the base of the branchlets on branches from the 

 middle of the tree upward, pale yellow; female near the ends of the branchlets of the 



Fig. 61 



upper branches only, with oblong scales rounded above and nearly as long as their cuneate 

 obcordate yellow-green bracts ending in slender elongated awns. Fruit on stout peduncles 

 sometimes \' long, oval or subcylindric, full and rounded at apex, glabrous, pale pur- 

 ple-brown, 3'-4' long, with thin scales strongly incurved above, obtusely short-pointed 

 at apex, obscurely denticulate on the thin margins, about one third longer than their 

 oblong-obovate obcordate pale yellow-brown bracts terminating in flat rigid tips I'-lf ' long, 

 above the middle of the cone pointing toward its apex and often closely appressed to its 

 sides, below the middle spreading toward its base and frequently much recurved, firmly 

 attached to the cone-scales and deciduous with them from the thick conical sharp-pointed 

 axis of the cone; seeds dark red-brown, about f long, and nearly as long as their oblong- 

 obovate pale reddish brown lustrous wings rounded at the apex. 



A tree, 100-150 high, with a trunk sometimes 3 in diameter, comparatively short 

 slender usually pendulous branches furnished with long sinuous rather remote lateral 

 branches sparsely clothed with foliage, forming a broad-based pyramid abruptly narrowed 

 15-20 from the top of the tree into a thin spire-like head, and stout glabrous light reddish 

 brown branchlets covered at first with a glaucous bloom. Winter-buds ovoid, acute, '-!' 

 long, \-\' thick, with very thin, loosely imbricated, pale chestnut-brown, acute, boat-shaped 

 scales. Bark becoming near the base of the tree z'-f ' thick, light reddish brown, slightly 



