300 WOOD AND FOREST. 



III. DIFFUSE-POROUS WOODS. 



(A few indistinctly ring-porous woods of Group II, D, and cedar elm may 

 seem to belong here.) 



A. Pores varying in size from large to minute; largest in spring wood, 

 thereby giving sometimes the appearance of a ring-porous arrangement. 



1. Heavy and hard; color of heart-wood (especially on longitudinal sec- 

 tion) chocolate brown BLACK WALNUT. 



2. Light and soft; color of heart-wood light reddish brown. .BUTTERNUT/ 



B. Pores all minute and indistinct; most numerous in spring wood, giving 

 rise to a lighter colored zone or line (especially on longitudinal section), 

 thereby appearing sometimes ring-porous ; wood hard, heart-wood vinous 

 reddish; pith rays very fine, but very distinct. (See also the sometimes 

 indistinct ring-porous cedar elm, and occasionally winged elm, which are 

 readily distinguished by the concentric wavy lines of pores in the sum- 

 mer wood ) CHERRY. 



C. Pores minute or indistinct, neither conspicuously larger nor more numer- 

 ous in the spring wood and evenly distributed. 



1. Broad pith rays present. 



a. All or most pith rays broad, numerous, and crowded, especially on 

 tangential sections, medium heavy and hard, difficult to split. 



SYCAMORE. 

 6. Only part of the pith rays broad. 



a/ Broad pith rays well defined, quite numerous; wood reddish 



white to reddish BEECH. 



&.' Broad pith rays not sharply defined, made up of many small 

 rays, not numerous. Stem furrowed, and therefore the periphery 

 of section, and with it the annual rings sinuous, bending in and 

 out, and the large pith rays generally limited to the furrows 

 or concave portions. Wood white, not reddish . . . BLUE BEECH. 



2. No broad pith rays present. 



IH 



?=fl 



m; a m fjjwffjS 



Fig. 135. Wood of Hickory. 



