340 ANATOMY OF THE GYMNOSPERMS 



the walls rather thin. Resin passages scattering, rather small, somewhat 

 numerous, chiefly in the summer wood; the epithelium in 1-2 rows of 

 large, rounded, thin-walled, often strongly resinous cells, which some- 

 times become thick-walled at the outer limits. Medullary rays not 

 numerous or prominent, rather narrow, i cell wide, distant 2-30 rows 

 of tracheids. 



Radial. Rays locally somewhat resinous, the resin massive ; the ray tra- 

 cheids strongly predominant, often composing the entire structure of the 

 low rays, in the higher rays marginal, more rarely interspersed, reticulated 

 in the summer wood. Ray cells of two kinds : * (i) rather frequent but 

 not predominant except in the low rays, rather high and long fusiform ; 

 the terminal walls thin, sometimes strongly pitted ; the upper and lower 

 walls rather thick and coarsely pitted ; the lateral walls with prominent 

 and very variable, oval, round, or lenticular pits, 1-4 per tracheid ; 

 and (2) cells resinous, the terminal, upper, and lower walls thin and 

 much broken out; the lateral walls with lenticular pits 1-3, chiefly 2, 

 per tracheid. Bordered pits in i row, sometimes in pairs, numerous, 

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

 wanting. 



Tangential. Fusifonn rays low, the terminals acute, rarely prolonged ; the 

 cells of the inflated portion large and rather thin-walled, often wholly 

 broken out. Ordinary rays low, rather broad, the cells very variable in 

 shape from oval to squarish, and presenting four principal aspects: (i) 

 low, fusiform in shape, composed of thick-walled, oval parenchyma cells 

 with terminal tracheids ; also higher rays of the same aspect ; (2) low 

 rays of thick- and thin-walled, oval parenchyma the latter resinous, 

 but otherwise not very different and small, terminal tracheids; (3) 

 higher rays of large, broad, thin-walled, resinous parenchyma, 1-2 thick- 

 walled parenchyma cells and terminal tracheids ; and (4) the highest 

 rays of thick-walled parenchyma and interspersed tracheids with local 

 contractions. Parenchyma cells oval, very narrow. 



A tree 24-36 m. high, with a trunk upwards of .90 in. in diameter. 

 Wood light, very strong and hard, coarse grained, and compact. 



Specific gravity 0.4942 



Percentage of ash residue 0.26 



Approximate relative fuel value 49.29 



Coefficient of elasticity in kilograms on millimeters . . . 1194. 



Ultimate transverse strength in kilograms 441. 



Ultimate resistance to longitudinal crushing in kilograms 8142. 



Resistance to indentation to 1.27 mm. in kilograms . . . 1950. 

 (Sargent) 



The coast ranges of California, reaching its greatest development in Men- 

 docino County. Rare and local, in cold peat bogs or barren, sandy 

 gravel below 2000 feet elevation (Sargent). 



1 The distinction between these two forms of cells is not very clear in this 

 species and is best expressed by the terms " thicker " and " thinner " as applicable 

 to elements which are not very different, or which merge by gradual transitions. 



