EXOGENOUS SERIES- BRO A OLE AF WOODS. 95 



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. There are so many hybrids and peculiar 

 species of willow that classification is often difficult (about one 

 hundred and forty species and varieties of the willow family 

 have been enumerated). Salix is said to be from the Celtic 

 Sal, meaning " near," and Z/*s, meaning " water." Salicylic 

 acid is present in the bark of some species. 



White Willow (Salix alba), naturalized in America, is very hardy 

 even in dry places. A valuable prairie wind-brake. Trees planted 

 several feet apart from good posts to support barbed wire. European 

 uses of the wood have been referred to. Salix alba has many 

 botanical varieties. 



