CHARACTERS OF LOUISIANIAN AREA. 



95 



centrally located .station where meteorological observations have been 

 made during- a series of years: 



The heat during the warmest season is tempered by the Gulf breezes 

 prevailing from forenoon to late in the afternoon. The Aapor-laden 

 currents from the Gulf in their unhindered sweep over the plain dis- 

 charge their moisture quite evenly throughout the year. 



It has been shown that man}^ of the plants frequent throughout the 

 Carolinian area and types characteristic of the southern exposures of 

 the Alleghany Mountains find their southern limit of vegetation on 

 the hills bordering upon the coastal plain. A similar limitation has also 

 been pointed out for a number of shrubs and trees, clearl}- marking 

 the border line between the Upper and Lower Austral life zones. 

 This zonal border, marked by trees strictly confined to the Louisianian 

 area of the Lower iVustral zone throughout its extent from east to west, 

 not only in Alabama, but from the Atlantic coast to the eastern border 

 of the Southwestern arid plains, deviates Ijut slightl}" from the line of 

 latitude 3!^° 30', and is clearly indicated bv the northwestern limit of 

 the following species: 



Magnolia foetida [M. grandiflora L.) (mag- 

 nolia) . 

 HicoriainyriMiraeformis (nutmeg hickory) . 

 Hicoria aquafica (bitter pecan) . 



Quercus laurifolia (laurel oak) . 

 Quercus lyrata (overcup oak) . 

 Quercus catesbaei (turkey oak) . 

 Pinus glabra (Southern spruce \nne) , 



The evergreens, consisting of pines on the light siliceous soils and 

 of broad-leaved species in the mesophile forest, predominate largely 

 over the deciduous forest growth, and the frequency of types identical 

 with tropical forms, or closely allied to them, impress upon the vege- 

 tation of this life area the character of the subtropical regions. 



The cultural plant formations of these regions, and confined within 

 the limits of this zone, are: 



Gossyplum herbaceum (cotton) . 



Zra mays (Indian corn) . 



Saccharitm offidnarum (tropical sugar 



cane) . 

 Oryza saliva (rice) . 

 Sorghum vulgare (Durrha, Kafir i-orn) . 



The growing of the cereals of this list replaces almost exclusively 

 the cultivation of small grain. 



Sorglmiii halcpeui^r (false (-ruinea or Jolm- 



son grass) . 

 J'eniciUaria sjyicala (cat-tail millet) . 

 Panicum barbinode (Para grass) . 

 Chaetochloa italica (Italian millet) . 



