PINUS 3 1 1 



Tangential. Fusiform rays rather numerous, chiefly small and narrow ; the 

 inflated portion with rather large and very thin-walled cells ; the resin 

 passage small. Ordinary rays low to medium, numerous, rather broad, 

 not restricted by the equal and occasionally interspersed tracheids ; 

 the cells chiefly equal, rather uniform, oval, chiefly narrow and thick- 

 walled, but sometimes with interspersed thin-walled cells often of 

 greater height. 



A small tree 6-9 m. high, with a trunk upwards of .90 m. in diameter. 

 Wood light, soft, not strong, brittle, close grained, compact, and durable in 

 contact with the soil. 



Specific gravity 0.6388 



Percentage of ash residue 0.62 



Approximate relative fuel value 63.49 



Coefficient of elasticity in kilograms on millimeters . . . 421. 



Ultimate transverse strength in kilograms 191. 



Ultimate resistance to longitudinal crushing in kilograms 5578. 



Resistance to indentation to 1.27 mm. in kilograms . . . 3388. 

 (Sargent) 



Eastern base of Pikes Peak, Colorado ; south through New Mexico to the 

 mountains of western Texas. Dry mesas and slopes, generally on lime or 

 sandstone, reaching elevations of 9000 feet in Colorado (Sargent). 



7. P. Lambertiana, Douglas 

 Sugar Pine 



Transverse. Growth rings narrow, uniform. Summer wood about one 

 fourth to one third the spring wood, from which the transition is 

 gradual, the structure rather open. Spring tracheids large, squarish- 

 hexagonal, in regular rows, very uniform, the walls thin. Medullary 

 rays not very prominent or numerous, rather broad, i cell wide, distant 

 2- 1 8 rows of tracheids. Resin passages very large, rather numerous, 

 the epithelium prominent, of several layers composed of very thin- 

 walled cells, very resinous. 



Radial. Rays barely if at all resinous ; the tracheids short, rather broad, 

 marginal and sparingly interspersed and then very narrow. Parenchyma 

 ray cells chiefly straight ; the upper and lower walls thin and obscurely 

 pitted ; the terminal walls thin and not pitted but sometimes locally 

 thickened ; the lateral walls with very large, oval pits, chiefly 2 per 

 tracheid throughout, rarely I or 3. Bordered pits distinctly in 1-2 rows, 

 elliptical, numerous. Pits on the tangential walls of the summer wood 

 numerous, but rather small and narrowly lenticular, not confined to the 

 outermost walls. Resinous tracheids wanting. 



Tangential. Fusiform rays numerous, large, and very broad, the inflated 

 portion composed of rather thin-walled, often strongly resinous, cells, the 

 very large resin passage with thin-walled epithelium. Ordinary rays 

 rather numerous, nonresinous, low to medium, strongly constricted at 



