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-LEAF 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 allof 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 OF 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- 
