ABIES 26l 



7. A. grandis, Lindl. 



ll'hilc Fir 



Transverse. Growth rings usually very broad, the structure rather open 

 throughout. Summer wood prominent, upwards of one eighth to one 

 fourth the very broad spring wood, into which it passes gradually, 

 the tracheids very unequal. Spring tracheids very large, thin-walled, 

 hexagonal, in regular rows, rather uniform. Resin cells few and scat- 

 tering on the outer face of the summer wood, nonresinous, distinguished 

 by (i) the sieve-plate structure of the terminal walls, and (2) their 

 somewhat advanced position. Resin-bearing tracheids more or less 

 numerous and scattering through the summer wood. Resin passages 

 wholly wanting. Medullary rays rather prominent and resinous, espe- 

 cially in the summer wood, i cell wide, distant 2-8, or rarely 10-12, 

 rows of tracheids. 



Radial. Rays more or less resinous throughout. Ray cells straight, becom- 

 ing contracted at the ends in the summer wood, equal to 4-6 spring 

 tracheids ; the upper and lower walls thin and entire or sparingly and 

 imperfectly pitted ; the terminal walls at first barely if at all pitted, 

 but at length coarsely pitted in the summer wood ; the lateral walls 

 with prominent but small oval pits, with an obscure border, the latter 

 becoming prominent toward the summer wood, where the broadly len- 

 ticular orifice becomes oblong, 1-2 throughout, or more rarely 4-6 in 

 the marginal cells. Bordered pits rather numerous in i row, ellip- 

 tical but variable, the orifice large. Resin-bearing tracheids rather 

 numerous and chiefly in contact with the rays, very resinous. Resin 

 cells on the outer face of the summer wood rather prominent, long, 

 and narrow, nonresinous, about equal to 20 /x wide and 135-310 /u, 

 long. Pits on the tangential walls of the summer tracheids somewhat 

 numerous, rather small and flat. 



Tangential. Rays rather numerous, low to high, broad, the rather large 

 cells more or less unequal, chiefly broadly oval, often squarish, fre- 

 quently resinous. 



A tree 61-92 m. high, with a trunk .90-1.50 m. in diameter. 

 Wood light, soft, not strong, coarse grained, compact. 



Relative specific gravity Q-3545 



Percentage of ash residue 0.49 



Approximate relative fuel value 35-8 



Coefficient of elasticity in kilograms on millimeters . . 958. 



Ultimate transverse strength in kilograms 211. 



Ultimate resistance to longitudinal crushing in kilograms 6255. 



Resistance to indentation to 1.27 mm. in kilograms . . 810. 

 (Sargent) 



Vancouver Island, south to Mendocino County, California, near the coast ; 

 interior valleys of western Washington and Oregon, south to the Umpqua 

 River, Cascade Mountains below 4000 feet elevation ; Blue Mountains of 

 Oregon ; Bitter Root Mountains of Idaho ; western slopes of the Rocky 

 Mountains of northern Montana (Sargent). 



