ECONOMIC "WOODS OF THE UNITED STATES 89 



(C, N); Scarlet Oak. cocdnea Muench. (C, N); 

 WiUow Oak. phellos L. (S). 



2 Pnrpg in 1a.t,f- ypffrl arrancrpH t.pnfrpnt^llY in COnspicUOUS 



festoons or concentric bands, usually continuous, wavy; 

 the pores minute or small. Pores inearly'wooHTn "single row 

 or in zone of 2-3 (rarely more) rows. Wood parenchyma 

 not in tangential lines. 



a Rays very d istinct; the larger 6-8 cells wide and 30-50 

 "T^sHS^IfigETc'ohspicuous; the smaller 1-2 cells wide and 6-10 

 cells high, inconspicuous; heterogeneous. , Heartwood 

 ^apparently absent or imperfectly developed. Textufeveiy" 



' coarse"""' """^ "^ 



a} Color yellow or grayish yellow. 



Hackberry. Celtis ocddentalis L. (C, N, S). 



b^ Color yellowish green. 



Sugarberry. C. mississippiensis Bosc. (S). 



b Rays rather indistin ct : the larger 3-5 cells wide and 15-30 

 cells high, appearmg much smaller than the larger rays of 

 the preceding; the smaller uniseriate and 3-5 cells high; 

 homogeneous. Heartwood distinct; color brown, often 

 \nth^reddish^tinge^ Texture~meclmm {o~coarse! "Elm. 



a' Pores in early wood forming a broad tangential band of 

 3 or more rows; pores large, numerous, conspicuous. 

 Texture coarse. Wood easy to split. (Iimer bark thick, 

 mucilaginous.) 



Slippery Elm. Ulmus pubescens Walt. (C, N, S). 



b' Pores in early wood usually in a single tangential row; 

 occasionally more in wide growth rings. 



a? Pores in early wood large, forming a continuous row 

 (Plate III, Fig. 2). Texture coarse. Wood difficult 

 to split. Rather light. 



White Elm. U. americana L. (C, N). 



b^ Pores in early wood small to minute, the larger ones 

 few and rather widely separated in a band of small 

 pores. Texture medium. Wood hard. 



a' Growth rings distinct. 



a^ Bands of small pores rather few; narrower 

 than intervening spaces. Wood very hard, com- 



