94 PLANT LIFE OF ALABAMA. 



extent. It is a shrub of a decidedly tropical habit, properly belonging 

 to the West Indian subgenus Eleuteria, from 10 to 15 feet high, 

 squarrosely branched from the base, and conspicuous by the scurfy 

 covering of silvery scales on the branchlets and lower sides of the 

 leaves. The flowers open from early in March to the middle of 

 April. By the end of the latter month the foliage of the previous 

 year is replaced by new leaves. It appears certain that this interesting 

 shrub is strictly confined to this secluded valley near the banks of 

 Little Cahaba River. The abundant white, star-like flowers of the 

 densely tufted Sedum nevii enliven the moss-covered rocks beneath 

 these thickets of Croton. This pretty plant is also found near Tusca- 

 loosa and is recorded from the mountains of southern Virginia and 

 from the Cumberland Mountains in Tennessee. Yeatesia laetevirens* 

 extending to northwestern Louisiana and eastern Texas, and Arabis 

 patem, extending to the Alleghenian area, occur on the shaded rocky 

 borders. Of xerophile plants, Campanula divaricata, frequent in the 

 Metamorphic and Coosa hills, is found on exposed cliffs with Gilia 

 coronopifolia, the latter ranging from the middle country of South 

 Carolina to the plains of Arkansas and Texas. Of rarer plants occur- 

 ring here are Marshallia lanceolata, ranging from Georgia to Tennessee 

 and North Carolina, and Silene regia, conspicuous by its rich panicles 

 of flaming scarlet flowers, also at home in the prairies of southern 

 Illinois and of the lower Ohio. Many a fern from the mountains 

 finds here the southern limit of its distribution on the rocky, shaded 

 banks of brooklets and streams. Of such may be enumerated: 



Phegopteris hexagonoptera. Asplenium filix-foemina. 



Asplenium ruta-muraria. Cheilanthes lanosa. 



Asplenium montanum. Cheilanthes alabamenxi*. 



Asplenium parvulum. Woodsia obtusa. 



Asplenium trichomanes. Dryopteris marginalia. 



LOUISIANIAN AREA OB FLORA. 



Descending from the hills of the older (Paleozoic) formations, con- 

 sisting of the extreme southern members of the Appalachian mountain 

 system, the Austroriparian or Louisianian area of the Lower Austral 

 life zone is reached. This area within the State is thus coterminous 

 with the vast Coastal plain. The elevation of this plain scarcely 

 exceeds at any point 350 feet above sea level, and in its gradual decline 

 to the Gulf shore presents great uniformity in its topography. Undis- 

 turbed by local influences due to great differences in elevation, the 

 distribution of heat here follows the lines of latitude. In consequence 

 the climate does not run to extremes. The following are data of tem- 

 perature and rainfall obtained at Greenville, Butler County, the most 



l Gatesia laeievirens A. Gray. 



