PINUS 315 



A tree 24-30 m. high, with a trunk sometimes exceeding .60 m. in diameter. 

 Wood light, hard, not strong, close grained, and compact. 



Specific gravity 0.4877 



Percentage of ash residue 0.26 



(Sargent) 



Rocky ridges and slopes of almost inaccessible canons at elevations between 

 6000 and 8000 feet. High mountains of southeastern New Mexico, to the 

 Santa Rita Mountains and the Santa Catalina Mountains of Arizona 

 (Sargent). 



11. * P. strobus, Linn. 



White Pine. Weymouth Pine 



Transverse. Growth rings usually thick. Summer wood usually thin, of 

 about 8 tracheids, rather conspicuous, variable and rather open, some- 

 times double ; the tracheids squarish, unequal in regular rows, the tran- 

 sition from the spring wood gradual. Spring wood open, the rather 

 large but very unequal tracheids distinctly hexagonal and thin-walled. 

 Medullary rays not very prominent or broad, i cell wide, few, distant 

 2-16, or more rarely 20, rows of tracheids. Resin passages numerous, 

 medium, the epithelium sparingly resinous. 



Radial. Rays nonresinous, the tracheids long and low, numerous, marginal 

 and sparingly interspersed when they are very low. Parenchyma ray 

 cells straight, equal to 6-1 5 spring tracheids ; the upper and lower walls 

 rather thickish and entire or distantly pitted ; the terminal walls thin 

 and entire or somewhat locally thickened ; the lateral walls with very 

 large, oval, or lenticular pits 1-2 per tracheid throughout, more rarely 

 3 per tracheid. Bordered pits rather numerous in i row, large, strongly 

 elliptical, much reduced, and finally obscure in the summer wood where 

 the orifice becomes a prolonged, diagonal slit. Pits on the tangential 

 walls of the summer wood numerous but small, chiefly narrowly lenticu- 

 lar. Resinous tracheids wanting. 



Tangential. Fusiform rays few, not very broad, nonresinous ; the cells of 

 the inflated portion large and thin-walled, often much broken out, or in 

 small branches often wholly wanting. Ordinary rays low to medium, not 

 very numerous, narrow, nonresinous ; the cells equal, rather uniform, 

 oblong, narrow, the side walls rarely convex, more generally concave. 



A large tree of the greatest economic value, 24-52 m. high, with a trunk 



upwards of 3.50 m. in diameter. 

 Wood light, soft, not strong, very close and straight grained, compact, 



easily worked, and susceptible of a beautiful polish. 



Specific gravity 0.3854 



Percentage of ash residue 0.19 



Approximate relative fuel value 38.47 



Coefficient of elasticity in kilograms on millimeters . . 851. 



Ultimate transverse strength in kilograms 267. 



Ultimate resistance to longitudinal crushing in kilograms 6219. 



Resistance to indentation to 1.27 mm. in kilograms . . 1194. 

 (Sargent) 



