KEY TO RING-POROUS WOODS. 67 



4. Pith rays fine but very conspicuous, even without magnifier. Color of heart- 

 wood red ; of sap wood pale lemon (No. 78) Honey locust. 



B. Pores of summer wood minute or small, in concentric wavy and sometimes branch- 



ing lines, appearing as finely-feathered hatchings on tangential section. 



1. Pith rays fine, but very distinct; color greenish white. Heartwood absent 

 or imperfectly developed (No. 70) Hackbkrry. 



2. Pith rays indistinct; color of heartwood reddish brown ; sapwood grayish 

 to reddish white ( Nos - 62 " 66 ) Elms - 



C. Pores of summer wood arranged in radial branching lines (when very crowded 



radial arrangement somewhat obscured). 



1. Pith rays very minute, hardly visible (Nos. 58-60) Chestnut. 



2. Pith rays very broad and conspicuous (Nos. 84-102) Oak. 



D. Pores of summer wood mostly but little smaller than those of the spring wood, 



isolated and scattered ; very heavy and hard woods. The pores of the spring 

 wood sometimes form but an imperfect zone. (Some diffuse-porous woods of 

 groups A and B may seem to belong here. ) 



1. Fine concentric lines (not of pores) as distinct, or nearly so, as the very tine 

 pith rays; outer summer wood with a tinge of red; heartwood light reddish 

 brown ( Nos - 71 - 75 ) Hickory. 



2. Fine concentric lines, much finer than the pith rays; no reddish tinge 

 in summer wood; sapwood white; heartwood blackish, 



(No. 105) Persimmon. 



ADDITIONAL NOTES FOR DISTINCTIONS IN THE GROl P. 



FlG.41.— A, black ash; B, white ash; G, green ash. 



The different species of ash may be identified as follows : 



1. Pores in the summer wood more or less united into lines. 



a. The lines short and broken, occurring mostly near the limit of the 

 rill(T (No 39) White ash. 



b. The lines quite long and conspicuous in most parts of the summer 

 ' woo ,i (No. 43) Green ash. 



2. Pores in the summer wood not united into lines, or rarely so. 



a. Heartwood reddish brown and very firm (No. 40) Red ash. 



b. Heartwood grayish brown, and much more porous.. (No. 41) Black ash. 



