142 THE FLORA OF MISSISSIPPI. 



Northeastern Prairie Belt. — The boundaries of this 

 region, and its relationship to other divisions can best 

 be had by reference to the sketch map inserted above. 



The region has a gently rolling surface, and was orig- 

 inally prairies, having only here and there scattered patches 

 of trees, except on the stream bottoms, where heavy timber 

 grew. The region is now largely in cultivation, but some 

 timber still remains in the bottoms. 



The characteristic soil of the prairies which is residual 

 from Cretaceous limestone, is a heavy, tenaceous, cal- 

 careous loamy clay, black when wet, dark gray when dry. 

 In much of the region a yellowish brown loam soil pre- 

 vails, which proabbly represents remnants of a very late 

 geological formation, the Columbian, or Brown Loam. 

 Occasionally an isolated eminence will show a capping of 

 the Brown Loam overlying a considerable thickness of 

 red sands. The vegetation shows variation with these 

 soil differences. The growth on the bottoms is very sim- 

 ilar to bottom land growth throughout the north half of 

 the state. 



As already stated, the black soils were originally prai- 

 ries devoid of tree growth except scattered clumps of crab 

 apple {Pyriis angustif alius) , honey locust {Gleditschia 

 triacanthos) , and along ledges, where the limestone comes 

 to the surface, red cedar (Juniperus Virginiana). On the 

 bluffs of streams are found very commonly hackberry 

 (Celtis Mississippiensis) , red bud (Cercis Canadensis), 

 rock maple (Acer saccharinum) , chestnut (Castanea vesca), 

 mulberry {Morus rubra). Common shrubs and creepers 

 in the same localities are: 



Aesculus pavia, Rhus Toxicodendron, 



Amorpha fruticosa, Cissus bipinnata, 



Wistaria fruticosa, Berchemia voluhilis, 



Ampelopsis quinque-Jolia, Rhus copallina. 



In the edges of the fields are such familiar species as 

 Apogon humilis. Cranium carolinianum , Valerianella radiata, 

 Anthemis cotula, O'^alis stricta, Vichondra repens, Rubus 



