108 PLANT LIFE OF ALABAMA. 
pine forests do not differ from those forming the soil cover in the 
open pine forests of the adjoining Lower Pine belt. 
Acrophile herbaceous plant association.—In the parts where the reac- 
tion of the decomposing limestone strata upon decaying vegetable mat- 
ter has produced soil conditions similar to those which prevail in the 
Central Prairie region (which includes the more or less calcareous lands 
of* the post oak prairies and cedar hammocks), the plant associations 
bear the same campestrian character, In Monroe and Clarke counties 
are found the same tall Compositae, together with various plants of 
other families, which are characteristic of that region. The following 
species are examples: 
Helianthus tomentosus. Lithospermum tuberosum. 
Helianthus hirsutus. Phacelia purshii. 
Silphium laciniatum. Verbena canadensis. 
Silphium asperrimum., Acuan (Desmanthus) brachycarpum. 
Silphium laevicaule. Morongia horridula. 
Lepachys pinnata. 
None of the above are met with farther south except the last two, 
which extend to the coast plain. Of xerophile and mesophile plants 
inhabiting shaded rocky dells and banks, the following find here their 
southern limit: 
Hepatica hepatica. Panax quinquefolia, 
Anemone decapetala. Collinsonia canadensis, 
Ranunculus recurvatus. Houstonia caerulea. 
On the damp rocks which line the narrow channels of brooks deeply 
cut into the limestone strata, the maidenhair fern (Adiantum capillus- 
venerds) occupies every crevice. Toward the southern confines of the 
region the following, which grow also in the adjoining region, are 
found: 
Sida elliottii. Clinopodium carolinianum. 
Callirhée papaver. Koellia albescens. 
Scutellaria canescens punctata. Stokesia laevis. 
On the limestone bluffs inclosing the bed of the Alabama River, for 
instance near Claiborne, Dérca palustris, ashrub from the Alleghenian 
area, finds in deeply shaded situations its extreme southern outpost. 
Philadelphus inodorus with Ptelea trifoliata and the river grape ( Vitis 
riparia) are also found on the bare ledges of these bluffs on the Oppo- 
site sides of the river. In the southwestern part of this region where 
the calcareous prairie soils are mixed with the light loams, the red 
cedar once formed a large portion of the timber growth, making a 
feature analogous to the cedar hammocks of the Central Prairie region. 
The cedar hammocks of this region are at present, however, nearly all 
under cultivation, and the few still covered with cedar are rapidly being 
stripped of their valuable timber, most! y for use as pencil wood. 
In the eastern extension of this region the loose Ozark sands form 
