Handbook of Trees of the Northern 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 thickn-ess, and these dimensions are at- 

 tained only by trios which are especially 

 favoifd hy soil and tliniate. When isolated 

 fidiii other trees il develojjs a rounded dome- 

 shaped or ubovuid top with wide sprcadin;,' 

 lateral branches and droojjing lower branches. 

 It is a singular fact tliat it is limited in dis- 

 tribution mainly to dry sandy barrens, the 

 conditions there, whieh most trees cannot tol- 

 erate, seeming to be what this tree actually 

 requires for its existence. Rare or local and 

 poorly developed in tlie northern part of its 

 range it is abundant southward, particularly 

 in the lower INIississippi 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 rounclod ami 

 entire or more or less 3-lobed and bristle-tipi)ed at 

 apex and rounded or cordate at tbe narrow ba-;e. 

 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. Flowers: staminate in slender hairy 

 aments : cal.yx with 4-5 broad lobes : anthers 

 apiculate ; pistillate flowers with rusty tomentose 

 peduncles. Fruit sessile or nearly so with suh- 

 globnsp acorns puberulous near apex and hnlf 

 covei-ed with the turbinate cup of rather thin 

 loosely imbricated pubescent scales. 



1. Syn. Qiicrciis nigra Wang. 



