22 



THE COMMERCIAL HICKORIES. 



erally from 7 to 9 leaflets. The fruit varies greatly in size and shape, 

 but commonly is spherical, with a thick husk and a thick-shelled nut, 

 sometimes strongly ridged and sometimes rounded, that contains a 

 small, rather rich kernel. The bark of the tree is never scaly. The 

 characteristic form in the lower Mississippi Valley has deep, diamond- 

 shaped checks or fissures and is light gray in color. Farther east the 

 bark becomes less ridged and the color is more whitish. The sapwood 

 is wide about 3 inches and is generally more than 50 years old. 

 The mockernut generally is smaller than either shagbark or pignut. 



The stem is less likely to be 

 straight, and the branches 

 are heavier. 



RANGE AND DISTRIBUTION. 



In the forest the hicko- 

 ries are rarely predomi- 

 nant. Except through the 

 interference of man, they 

 do not grow in pure stands 

 but always in mixture, 

 somewhat group-wise, 

 with other species, and 

 especially with the oaks. 

 The accompanying maps 

 show the botanical and 

 commercial ranges of the 

 different species of the 

 pecans and of the true 

 hickories. 



The botanical ranges show the regions in which the species grow 

 naturally. 



The three salient points of the botanical distribution are the com- 

 paratively narrow, southern range of the pecan hickories (except the 

 frost-hardy bitternut), confined by the need for warmth and moisture 

 to the river bottoms of the Mississippi Valley and Gulf regions; the 

 wide distribution of the true hickories, especially the pignut and the 

 shagbark ; and the centering of the distribution of nearly all the species 

 in the lower Mississippi Valley, in western Tennessee, eastern Arkan- 

 sas, and northwestern Mississippi. 



The commercial distributions show the regions within which the 

 hickory is of sufficient importance to be a factor in forest manage- 

 ment. Of all the species, shagbark and pignut are most widely and 

 evenly distributed, and these two furnish the bulk of the hickory of 

 commerce. Shagbark is fairly common in the wood lots of southern 



FIG. 9. Mockernut (Hicoria alba). Twig, natural size; leaf 

 and fruit, one-third natural size. 



