EXOGENOUS SERIES- BROADLEAF WOODS. 89 



Black Willow. Salix nigra Marsh. 



Nomenclature. (Sudworth.) 



Black Willow (local and com- Willow (N. Y., Pa., N. C., 



mon name). S. C., Miss., Tex., Cal., 



Swamp Willow (N. C., S. C.). Ky., Mo., Neb.). 



Locality. 



New Brunswick to Florida, westward intermittently to Dakota, 

 Arizona, and California, Mexico. 



Features of Tree. 



Forty to fifty feet in height, two to four feet in diameter. Long 

 narrow leaf, characteristic appearance. 



Color, Appearance, or Grain of Wood. 



Heartwood brown, sapwood nearly white, close-grained. 



Structural Qualities of Wood. 



Soft, light, weak, checks badly in drying, readily worked. 

 Dents without splitting. 



Representative Uses of Wood. 



Lap-boards, basket-making, fuel, charcoal. 



Weight of Seasoned Wood in Pounds per Cubic Foot. 



27. 

 Modulus of Elasticity. 



550,000. 

 Modulus of Rupture. 



6000. 



Remarks. 



Prefers borders of rivers and bottom lands. Many varieties of 

 willow grow in the United States. No one is used to any 

 extent in construction. 



