PINUS 323 



Sandy dunes and exposed rocky points, everywhere on the coast of British 

 Columbia ; when sheltered growing in groves ; rarely found in the 

 Queen Charlotte Islands (Macoun) ; Alaska and southward from Britisli 

 Columbia along the coast to Mendocino County, California, and inland 

 to the western slopes of the coast ranges (Sargent). 



19. P. glabra, Walt. 

 Cedar Pine. Spruce Pine. White Pine 



T'ransverse. Growth rings thick. Summer wood of about one half the 

 spring wood, from which the transition is usually somewhat abrupt, 

 double or treble, the central portions dense, the outer portions open, 

 especially when double or treble ; the tracheids rather variable, in 

 regular rows. Spring tracheids hexagonal, uniform in regular rows, 

 the walls thin. Resin passages rather abundant, medium ; the epi- 

 thelium in 1-2 rows of large, rounded and thin-walled, resinous and 

 irregular cells usually much broken out, but not forming very extended 

 tracts. Medullary rays not very broad, prominent, or numerous, distant 

 2-12 rows of tracheids. 



Radial. Rays very sparingly resinous, the tracheids sparingly icticulated, 

 often predominant and interspersed. Ray cells of two kinds : (i ) rather 

 rare ; and (2) the terminal, upper, and lower walls very thin and often 

 apparently wanting ; the lateral walls with lenticular, variable pits, 1-6, 

 chiefly 2 or 3, per tracheid, in the summer wood finally reduced to i 

 and becoming a short slit. Bordered pits in i row, elliptical, in the 

 summer wood soon reduced to 9.6 /JL, the orifice often much prolonged, 

 sometimes rather large and bordered. Pits on the tangential walls of 

 the summer wood wholly wanting. 



Tangential. Fusiform rays not numerous, medium ; the terminals acute, or 

 slightly prolonged and composed of small tracheids ; the inflated por- 

 tion composed of thin-walled cells all broken out. Ordinary rays chiefly 

 low to medium, somewhat numerous, and presenting two principal 

 aspects: (i) rays composed of large, thin-walled parenchyma cells 

 much broken out, and few, small, terminal tracheids ; and (2) rays 

 composed of large, thin-walled parenchyma cells with terminal and 

 interspersed, chiefly predominant and narrower, tracheids causing local 

 contraction. 



A tree 24-30 m. high, with a trunk upwards of 1.20 m. in diameter. 

 Wood light, soft, not strong, brittle, very coarse grained, not durable. 



Specific gravity 0.3931 



Percentage of ash residue 0.45 



Approximate relative fuel value 39. 1 3 



Coefficient of elasticity in kilograms on millimeters . . 448. 



Ultimate transverse strength in kilograms 212. 



Ultimate resistance to longitudinal crushing in kilograms 4604. 



Resistance to indentation to 1.27 mm. in kilograms . . 1694. 

 (Sargent) 



