98 ECONOMIC WOODS OF THE UNITED STATES 



parenchyma in indistinct tangential lines. Pores 

 crowded. Color light brown, often with dark 

 stripes or "feather grain." Wood medium to 

 heavy, moderately hard, usually cross-graiued, 

 difficult to split. Sycamore or Buttonball. Pla- 

 tanus occidentalis L. (C, N, S), racemosa Nutt. 

 (Ps), wrightii Wats. (Rs). 



b' With only part of the rays broad; variable; 

 irregularly distributed; intermediate rays visible, 

 mostly uniseriate; heterogeneous. " Silver grain" 

 less conspicuous than in preceding. Wood paren- 

 chyma in indistinct tangential lines. Pores 

 crowded. Color pale reddish brown to white with 

 reddish tinge; uniform. Wood heavy, hard, 

 strong, usually fairly straight-grained. 



Beech. Fagus americana Sw. (C, N, S). 



b' Without conspicuously broad rays. 



a^ Rays very distinct; variable, 1-7 cells wide. 



a' Wood fibres with spirals. 



a* Color chalky white. Pores irregularly distrib- 

 uted in long radial lines. Vessels with spirals; 

 perforations scalariform. Rays colorless; hete- 

 rogeneous. Wood parenchyma not in distinct 

 lines. Wood of medium weight, hard and 

 tough. Holly. Ilex opaca Ait. (S, C). 



b' Wood fibres without spirals. 



a* Wood parenchyma not in tangential lines. 

 Vessels with spirals; perforations simple. 



a^ Color rich reddish brown or vinous. Pores 

 numerous, solitary, or in groups, often radial, 

 of 2-6; usually more abundant in early wood, 

 producing a light-colored line of demarcation 

 between growth rings. Vessels plugged at 

 intervals with dark red gum. Rays mostly 

 3-5 cells wide, occasionally uniseriate; few 

 to 100 cells high; producing fine but con- 

 spicuous "silver grain" on radial surface. 

 Wood moderately heavy, hard, and strong. 



