90 PLANT LIFE OF ALABAMA. 



the limit of the metamorphic hills. The change in the character of 

 the flora in this ill-defined region is indicated by the absence of or 

 decrease in the number of species possessed in common with the north- 

 ern Alleghanies and the Ohio Valley and the appearance of Southern 

 forms which never or but rarely occur in the mountain region. These 

 hills have a number of species in common with the northern extension 

 of the Carolinian area which find their southern limit in this region 

 and impart to its flora a northern aspect. For this reason it might 

 botanically be regarded as a subdivision of the mountain region of 

 which these lower hills in their descent to the Coastal plain form the 

 last terrace and of which stratigraphically they are an integral part. 



GRAVELLY HILLS OF SHORT-LEAP PINE AND HARDWOOD TREES. 



On the western descent of the Warrior table-land the coal measures 

 disappear under heavy deposits of sand and gravels of a more recent 

 formation, through which the water courses have cut their beds, result- 

 ing in the formation of rounded hills from 250 to a little over 300 feet 

 high down to low undulating ridges, of considerable length and width 

 between the hills. This belt of drifted deposits extending along the 

 western border of the State across the Tennessee River forms the 

 divide between the waters of the Tombigbee River and the Warrior 

 basin, and is the northern extension of the central belt of drifted 

 deposits which separates the older from the recent geological forma- 

 tions. It embraces nearly all of Colbert, parts of Franklin and Marion, 

 all of Lamar, the western section of Fayette and Pickens, and the 

 northwestern part of Tuscaloosa counties. Notwithstanding the dif- 

 ferences in its geological condition, this subdivision can not well be 

 separated botanically from the floral region under consideration. This 

 upland area is at once distinguished by the frequency of the shortleaf 

 pine among the hardwood trees, mostly upland oaks and hickories, 

 the pine having originally constituted about one-half of the tree growth. 

 This proportion has, however, during later years, been greatly reduced, 

 and the supply of pine timber is at present nearly exhausted. The 

 forest presents almost the same aspect as that found on the table-lands 

 at or below the elevation of about 800 feet above the sea, which have 

 a similar light and dry soil. 



These gravelly hills, being closely connected with the Tennessee Val- 

 ley and with the mountain region through the numerous prongs of the 

 western edge of the Warrior table-land intersecting this subdivision, 

 its herbaceous flora, mostly of the xerophile class, presents no peculiar 

 characteristics. 



COAL MEASURES OP THE CAHABA VALLEY AND WARRIOR BASIN. 



Crossing the southern rim of the Warrior coal basin and the Cahaba 

 coal field an extremely hilly area is entered, most rugged along its 

 southern borders. It comprises the eastern part of Marion and Fay- 



