338 ANATOMY OF THE GYMNOSPERMS 



fusiform, the terminal, upper, and lower walls thin and usually much 

 broken out; the lateral walls with lenticular or oval, very variable 

 pits, 1-4, chiefly 2 or 3, per tracheid, in the summer wood becoming 

 distinctly bordered, the orifice an extended slit, conterminous with 

 tracheids and cells of the first order. Bordered pits in i row or pairs, 

 elliptical, and toward the summer wood soon replaced by narrow slits, 

 which often lead into strong, double striations. Pits on the tangential 

 walls of the summer wood wholly wanting. 



Tangential. Fusiform rays not numerous, low and broad, the chiefly acute 

 terminals composed of a few tracheids ; the cells of the inflated portion 

 very thin-walled, chiefly broken out, or again rather thick-walled in part 

 and persistent. Ordinary rays low to medium and presenting four prin- 

 cipal aspects : ( i ) low rays of thin-walled parenchyma, much broken out, 

 and small, terminal tracheids; (2) low rays of thick-walled parenchyma 

 and small, terminal tracheids ; (3) higher rays of thick-walled paren- 

 chyma and both terminal and interspersed tracheids with occasional 

 thin-walled parenchyma ; and (4) the highest rays of thin-walled, resin- 

 ous, and interspersed thick-walled parenchyma, together with terminal 

 and interspersed tracheids. 



A tree 9-18 m. high, with a trunk upwards of 1.05 m. in diameter. 

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



Specific gravity 0.4935 



Percentage of ash residue 0.27 



Approximate relative fuel value 49.22 



Coefficient of elasticity in kilograms on millimeters . . 803. 



Ultimate transverse strength in kilograms 310. 



Ultimate resistance to longitudinal crushing in kilograms 5670. 



Resistance to indentation to 1.27 mm. in kilograms . . . 1842. 

 (Sargent) 



Allegheny Mountains, Pennsylvania to Tennessee, in the high mountains of 

 the latter attaining its greatest development (Sargent). 



35. P. inops, Ait. 



Jersey Pine. Scrub Pine 



Transverse. Growth rings thick, often double. Summer wood rather dense, 

 sometimes more or less open, equal to about one fourth or one third the 

 spring wood, from which the transition is usually abrupt ; the tracheids 

 strongly unequal, chiefly in regular rows. Spring tracheids squarish, 

 large, very uniform in regular rows, the walls thin. Resin passages 

 rather numerous, medium; the epithelium in 1-2 rows of large, round, 

 thin-walled or again rather thick-walled, resinous cells, which are often 

 developed eccentrically about the canal, and become thicker-walled 

 especially on the outer limits. Medullary rays prominent, rather broad, 

 i cell wide, not numerous, distant 2-12 rows of tracheids. 



Radial. Rays somewhat resinous, the resin massive, localized ; the tracheids 

 numerous, low, very variable and very strongly reticulated throughout, 

 predominant, often interspersed. Ray cells of two kinds : (i) the terminal 



