THE FLORA OF MISSISSIPPI. 145 



Characteristic shrubs of the lowland forests are: 



Asimina triloba, Cissus hipinata, 



Aesculus glabra, Arundinaria, 



Berchemia volubilis, Lonicera sempervirens, 



Cephalanthus occidentalis, Azalea nudiflora (rare). 

 Tecoma radicans. 



So far no great diversity has been noted in the herba- 

 ceous flora of the river bottoms. In the open wet forests 

 the following are frequent: 



Clematis crispa, Polymnia Uvedalia, 



Viola cucullata, Saururus cernuus, 



Arisaema quinatum, Osmunda cinnaniomea, 



Dioscorea villosa, Allium cernuum. 



Ranunculus nitida, Pentstemon laevigatus, 



Phlox divaricata, Ranunculus pusillus, 



Thaspium barbinode, Ilysanthes gratioloides. 

 Smila X Pseudo- China, 



On open lowland fields a very characteristic form is 

 Oenothera triloba. Its tufted rosette of leaves and its|large 

 lemon -yellow flowers make it very conspicuous. 



Pontotoc Ridge. — The next topographic and soil di\dsion 

 to be recognized consists of a series of high ridges running 

 north and south, and having the distribution shown in 

 the map. The soils are red sandy loams derived from 

 weathering of the Ripley marls of Cretaceous age. These 

 red soils are much richer in plant food than their appear- 

 ance would indicate, and the plants of the Pontotoc Ridge 

 present decided differences from the prairies lying to the 

 east and the Flatwoods on the west. The northern part 

 of the Ridge is much broken into hills about the head- 

 waters of the Hatchie River, the soil is sandy and rather 

 sterile, so that the growth partakes largely of the charac- 

 ter of the red sand hiUs of the prairie belt. Pines (Pinus 

 mitis and P. taeda) are the principal tree growth, but with 

 a considerable admixture of oaks {Quercus stellaia, Q. nigra, 

 Q. falcata) and chestnut (Castanea vesca). In the more 

 typical soil of this region found from New Albany south- 



