ECONOMIC WOODS OF THE UNITED STATES 97 



b^ Wood light, soft, not strong. Odorless. Color light 

 chestnut brown with dark tangential zones. Sap- 

 wood very thin. Butternut. J. cinereaL. (C, N).*'* 



b Pores very small to minute, indistinct, usually fairly uni- 

 form in size and distribution throughout growth ring. 



a' With conspicuously broad rays. 



a? Broad rays rather few, appearing as aggregated small 

 rays (Plate V, Figs. 3, 4). Wood without "silver 

 grain." 



a' Broad rays grouped, confined to short radii. Inter- 

 mediate rays abundant, very fine, indistinct, 

 irregular. Wood parenchyma in indistinct tan- 

 gential lines. Pores in early wood in irregular 

 groups which appear to unaided eye as white dots; 

 not crowded; arrangement somewhat obliquely 

 radial; pores fewer and smaller in late wood. 

 Vessels with spirals. Growth rings decidedly un- 

 dulating. Color yellowish white. Wood heavy, 

 hard, very tough, difficult to split. 

 Blue Beech. Carpinus caroliniana Walt. (N, C).** 



b^ Broad rays distant, fairly evenly distributed. 

 Intermediate rays very numerous, uniseriate, in- 

 visible to unaided eye. Wood parenchyma not in 

 tangential lines. Pores more numerous in early 

 wood, showing slightly radial arrangement; some- 

 what crowded. Vessels without spirals. Growth 

 rings not imdulating or only slightly so; not very 

 clearly defined. Color light brown tinged with 

 red; exposed surface of lighter colored sap wood 

 soon stained reddish brown upon exposure. Wood 

 light, soft, moderately strong, brittle. Red Alder. 

 Alnus oregona Nutt. (P) (Plate V, Figs. 3, 4)." 



b^ Broad rays numerous, non-aggregated. Wood with 

 conspicuous "silver grain" on radial surface. 



a' Rays practically all broad, mostly 10-15 cells; 

 abimdant; fairly regularly disposed; of deeper 

 color, than surrounding tissue, producing very con- 

 spicuous "silver grain"; homogeneous. Wood 



