PINUS 309 



A small tree 15-19 m. high, with a trunk upwards of .90 m. in diameter. 

 Wood light, soft, weak, brittle, very close grained, compact, satiny, and 

 susceptible of a good polish. 



Specific gravity Q-5434 



Percentage of ash residue .... 0.41 



Approximate relative fuel value 54-17 



Coefficient of elasticity in kilograms on millimeters . . 594. 



Ultimate transverse strength in kilograms 181. 



Ultimate resistance to longitudinal crushing in kilograms 5398. 



Resistance to indentation to 1.27 mm. in kilograms . . 2350. 

 (Sargent) 



Dry, open ridges, forming upon Scott's Mountain a broad belt of open 

 forest between 5000 and 8000 feet elevation. Mt. Whitney, California, 

 and about the head waters of the King and Kern rivers (Sargent). 



5. P. aristata, Engelm. 



Foxtail Pine. Hickory Pine 



Transverse. Summer wood thin, upwards of 8 tracheids, barely distinguish- 

 able, very open, the tracheids often variable in more or less conspic- 

 uously irregular rows. Spring tracheids rather large, conspicuously 

 squarish-hexagonal, very uniform in regular rows, the walls thin, the 

 transition to the summer wood very gradual. Medullary rays rather 

 prominent and broad, i cell wide, distant 2-6, more rarely 10, rows of 

 tracheids. Resin passages numerous, rather large, the rather exten- 

 sive and many-layered epithelium composed of large, very thin-walled, 

 nonresinous cells. 



Radial. Rays sparingly resinous throughout ; the tracheids numerous, mar- 

 ginal, sparingly interspersed. Parenchyma ray cells of 2 kinds : (i) the 

 cells more or less strongly contracted at the ends ; the upper and lower 

 walls thick, strongly pitted ; the terminal walls coarsely pitted ; the 

 lateral walls with round or oval but rather small pits, with a lenticular 

 orifice and an obvious border which becomes variable and obscure 

 toward the summer wood, at first 3-6, soon uniformly about 4, or in 

 the outermost summer wood 2, per tracheid ; and (2) cells occasionally 

 interspersed and often conterminous with the cells of the first kind ; 

 the terminal walls thin and not pitted, but often locally thickened ; 

 the upper and lower walls thin and not pitted ; the lateral walls devoid 

 of pits. Bordered pits numerous, in i row, elliptical, as broad as the 

 tracheid. Pits on the tangential walls of the summer wood chiefly 

 confined to the outermost wall, where they are numerous, apparently 

 not extending beyond the second wall, small, distinctly lenticular. 

 Resinous tracheids wanting. 



Tangential. Fusiform rays rather few, narrow, the cells of the short termi- 

 nals thick-walled, those of the inflated portion very thin-walled and 

 much broken down or wanting, the more persistent central tract with 

 a rather small resin passage with delicate epithelium. Ordinary rays 



