ECONOMIC WOODS OF THE UNITED STATES 81 



Color yellowish to reddish or orange brown. 

 Sapwood very thick. 



Loblolly Pine. P. tceda L. (S).' 



b' Wood^comBarativelyJight, soft, n ot stron g, brittle. 

 Xexture usually coa^, occasionally medium to 

 fine. Sapwood usually thick; rarely thin. P 

 murrayana "O. C." (R, P); -ponderosa Laws. (R, 

 P) ; radiata Don. (P)"; attenuata Lem. (P) ; sahi- 

 niana Dougl. (P)'"; coulteri Lamb. (P); torreyana 

 Parry (P); chihuahuana Eng. (R); arizonica 

 Eng. (R) ; rigida Mill. (N) ; divaricata Ait. (N) ; 

 pungens Michx. f. (N); clausa Sar'g. (S); glabra 

 Walt. (S); virginiana Mill. (C, S)." 



a* Tangential surf ace showing conspicuous "peb- 

 bly" or "bird's-eye" grain. Resin du cts very 

 small, s catteri ng. Texture fine . Color light , 

 yellow or nearly white. Sapwood thin. Prop- 

 erties of wood fairly uniform. Lodgepole 

 Pine. P. murrayana "0. C." (R, P). 



b* Tangential surface usually normal. Resin 

 ducts comp arativelv largejjjdjnumerous. Tex- 

 ture medium to coarse. Color widely variable 

 from pale lemon to orange brown. Sapwood 

 thick. Wood variable from heavy, hard, and 

 coarse to light, soft, fine, and non-resinous 

 Jik*^ white pine . Western Yellow Pine. P. 

 ponderosa Laws. (R, P).'^ 



b Resin ducts mostly inconspicuous, not numerous, irregularly 

 distributed or grouped; chiefly without tyloses; epithelium 

 thick-walled. Resin cells inconspicuous, near the outer 

 limit of the late wood. , 



a' .Resin ducts, very small, .mostly invisible to unaided eya ; 

 round in cross section. Marked contrast in color be- 

 tweea-heartwood._and sapwood.. Sapwood thin. Tra- 

 cheids without spirals.* 



a? Colpr yellowjsll Jtcosai- Texture medium. 



"^ Tamarack. Larix americana Michx. (N). 



* The occasional occurrence of spirals in the tracheids of the late wood of 

 Larix has been noted by Bailey, Bot. Gaz., Vol. XLVIII, pp. 47-55. 

 6 



