PINUS 341 



37. P. insignis, Douglas 

 Monterey Pine 



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

 the transition from the spring wood very gradual ; the tracheids very 

 unequal in more or less irregular rows, often strongly compressed radi- 

 ally. Spring tracheids hexagonal, very unequal in somewhat regular 

 rows, the walls medium. Resin passages scattering, numerous, rather 

 large ; the epithelium in 1-3 rows of very large, round, but variable and 

 rather thin-walled, resinous cells. Medullary rays very prominent, broad, 

 i cell wide, not very numerous, distant 2-12, more rarely 21, rows of 

 tracheids. 



Radial. Rays resinous, the resin localized, granular, more rarely massive 

 or in the cell wall ; the ray tracheids sparingly reticulated and sparingly 

 predominant, when interspersed, very low and unequal. Ray cells of 

 two kinds: (i) cells usually low and prominent, especially in the low 

 rays ; the terminal walls often thick and coarsely pitted ; the upper and 

 lower walls very variable, in the low rays thick and coarsely pitted, in 

 the higher rays thin and barely pitted so as to approach cells of the 

 second order ; the lateral walls with variously oval or lenticular pits, 

 1-2, rarely 6, chiefly 2, per tracheid ; (2) cells straight or variously 

 fusiform; the terminal, upper, and lower walls very thin, commonly 

 much broken out ; the lateral walls with broadly oval or variously len- 

 ticular pits, 1-3 per tracheid, in the summer wood reduced to much- 

 prolonged slits. Bordered pits in i row, sometimes in pairs, elliptical. 

 Pits on the tangential walls of the summer wood wholly wanting. 



Tangential. Fusiform rays somewhat abundant, medium, rather narrow, the 

 terminals acute or somewhat prolonged, chiefly composed of small tra- 

 cheids ; the cells of the inflated portion chiefly thin-walled and usually 

 much broken out, but dark and resinous. Ordinary rays medium, rather 

 broad, composed of thicker- and thinner-walled cells and presenting four 

 principal aspects: (i) low rays composed of thick-walled parenchyma 

 and tracheids, distinctly fusiform ; (2) i-seriate rays composed of sev- 

 eral cells of thick-walled parenchyma and tracheids, usually nonresinous ; 

 (3) i-seriate rays composed of terminal tracheids, thick-walled and 

 thin-walled parenchyma, usually much broken out through the central 

 region, more or less resinous ; and (4) the highest rays showing inter- 

 spersed, narrow tracheids with strong, local contractions. 



A tree 24-30 m. high, with a trunk upwards of .90 in diameter. 

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



Specific gravity Q-4574 



Percentage of ash residue -3 



Approximate relative fuel value 45-6 



Coefficient of elasticity in kilograms on millimeters . . . 979. 



Ultimate transverse strength in kilograms 316. 



Ultimate resistance to longitudinal crushing in kilograms 6680. 



Resistance to indentation to 1.27 mm. in kilograms . . . 1687. 

 (Sargent) 



Rare and local, on sandy soil in proximity to the seacoast, California (Sargent). 



