CLASSIFICATION OF HARD-WOODS. 65 



Sapwood white : heartwood light brown, lus- 

 trous : rings angular : vessels 1 5 together. 

 Black Poplars or Cotton woods, Pdpulus nigra, 

 moniltfera, balsamifera. 

 Rings circular : vessels 1 7 together. 



| Without pith-flecks : heartwood yellow-brown. 



White Poplar, Pdpulus alba. 

 1 1 With white pith-flecks : white, with no distinct 

 heartwood. Aspen, Pdpulus trdmula. 



