PIandbook of Teees of the Northekn States and Canada. 155 



The Black Jack Oak is a tree of medium size, 

 occasionally altainini; the height of 40 or 50 

 ft., willi a trunk larely more than 18 in. or 2 

 ft. in thiekp-(vs. and these dimensions are at- 

 tained only by trees whieli are especially 

 favored hy soil and climate. When isolated 

 fioni other trees it de\elo[is a rounded douie- 

 sliapcd or obovoid to[i with wide spreading 

 lateral branches and droo[iiug lower branches. 

 It i^ a singular fact that it is limited in dis- 

 tributicm mainly to dry saudy barrens, the 

 conditions there, which most trees cannot tol- 

 erate, seeming to be what this tree actually 

 retpares for its e.Kistence, liare or Icical and 

 poorly develo[ied iu the northern part of its 

 range it is abundant southward, particularly 

 intlu' lower Jlississippi Valley, wdiere itattain.s 

 its largest dimensions. Its singular dark green 

 glo--;y 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 wdien absolutely dry weigli- 

 ing 45.04 lbs., and is little used except for find 

 and charcoal, for which it is excellent. 



Leaves obovate. very broad and rouudcd and 

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

 apex and rounded or cordate at the nari-ow base. 

 Wlien youoi;- stellate-pubescent aliove and rusty 

 touientriS(^ beneatti, aint at maturit,\- tliick an<i 

 iHstrons darl; green above, yellowish and scurfy 

 pubescent beneath : petioles short, stout and 

 pubescent, Ftoircrs: stamlnate In slender hairy 

 araents ; calyx with 4-5 broad lobes: Rutbc's 

 apiculate; pistillate flowers with rusty tomi'ntos(> 

 peduncles. Fruit sessile or nearly so wilb sub- 

 globose acorns pubernlous near ape.t and hnit 

 rnvrird wMb tbc liirliinale cup of rather thin 

 lonsi'lv imbricated pubescent scales. 



1. Syn. Qucrciis niora Wang. 





