96 



Fimbristylis puberula Anthaenantia villosa 



Fimbristylis laxa Trilisa odoratissima 



Gerardia filifolia? Chaptalia tomentosa 



Afzelia cassioides Agave (Manfreda) virginica 



Muhlenbergia expansa 



Lichens 

 Cladonia sp. 



Nearly all of these plants are common in ordinary dry pine- 

 barrens in the neighborhood, the only ones especially character- 

 istic of the rocks being the Chondrophora, Crotonopsis, Fim- 

 bristylis laxa, and perhaps the Panicum and Agave. 



Next to the wire-grass, our Chondrophora seemed to be the 

 most abundant plant. It was in bloom at the time, and I 

 secured plenty of specimens, which agree with those from 

 Georgia and Alabama in every particular. 



In some places on the slopes of Rock Hill a little water seeps 

 out, making a suitable habitat for a moist pine-barren flora, of 

 the kind that is characteristic of Southeast Georgia, West 

 Florida, etc. One of the commonest plants in such habitats, 

 from North Carolina to Mississippi, is Chondrophora nudata. 

 Here at Rock Hill, as well as in Crisp County, Georgia,* it 

 could sometimes be found within a few feet of its rock-loving 

 relative; and there being no marked difference between them 

 except in the width and number of their basal leaves, they could 

 hardly be distinguished a few feet away. 



This suggests an interesting problem in evolution. If Chon- 

 drophora virgata were known only from the two localities last 

 mentioned, one might reasonably assume' that it was merely a 

 narrow-leaved extreme of the common C. nudata, developed in 

 direct response to its rocky habitat. But the fact that it is 

 most abundant in the mountains of Alabama, far removed from 

 any C. nudata (which is strictly confined to the coastal plain, 

 and does not even approach the fall-line very closely, as far as 

 known), would seem to make this hypothesis untenable. For 

 all we know, our plant may have been growing on the Carbonifer- 

 ous sandstones long before the coastal plain — or the pine-barren 



*See Bull. Torrey Club 32: 168. 1905. What is now Crisp County was then 

 included in Dooly. 



