Handbook of Tbees of the JSToETHEBisr States and Canada. 155 



The Black Jack Oak is a tree of medium size, 

 occasionally attaining the height of 40 or 50 

 ft., with a trunk rarely more than 18 in. or 2 

 ft. in thickness, and these dimensions are at- 

 tained only by trees which are especially 

 favored by soil and climate. When isolated 

 from other trees it develops a rounded dome- 

 shaped or obovoid top with wide spreading 

 lateral branches and drooping lower branches. 

 It is a singular fact that it is limited in, dis- 

 tribution mainly to dry sandy barrens, the 

 conditions there, which most trees cannot tol- 

 erate, seeming to be what this tree actually 

 reqviires for its existence. Rare or local and 

 poorly developed in the northern part of its 

 range it is abundant southward, particularly 

 in the lower Mississippi Valley, where it attains 

 its largest dimensions. Its singular dark green 

 glossy leaves, tufted at the ends of the branch- 

 lets, are pleasing and familiar objects within 

 its range even to those who only casually 

 observe trees. 



The wood of the Black Jack is hard and 

 heavy, a cubic foot when absolutely dry weigh- 

 ing 45.64 lbs., and is little used except for fuel 

 and charcoal, for which it is excellent. 



Leaves obovate, very broad and rounded and 

 entire or more or less 3-lobed and bristle-tipped at 

 apex and rounded or cordate at the narrow base. 

 When young stellate-pubescent above and rusty 

 tomentose beneath, and at maturity thick and 

 lustrous dark green above, yellowish and scurfy 

 pubescent beneath ; petioles short, stout and 

 pubescent. Floicers: staminate in slender hairy 

 aments ; calyx with 4-5 broad lobes ; anthevs 

 apiculate ; pistillate flowers with rusty tomentose 

 peduncles. Fruit sessile or nearly so with sub- 

 globose acorns puberuloua near apex and half 

 covered with the turbinate cup of rather thin 

 loosely imbricated pubescent scales. 



1. Syn. Quercus nigra Wang. 



