81 



Aspleniiwi rcsiliens is most noteworthy because of its appearance 

 at seven stations. With two exceptions these all seem to be new 

 records for the state/ Cheilanthes alabainensis, too, was found 

 only on limestone but apparently it is not as adaptable as Asplenium 

 resiliens for it occurred at only two stations. Finally Asplenium 

 cryptolepis and Carcx plantaginea were found each at one station 

 growing directly upon limestone. 



Discussion and Summary 



In a survey of the infrequent limestone outcrops of North 

 Carolina, nine were located and studied botanically. All are in the 

 mountains in the western part of the state and are within the 

 general range of numerous species which are restricted to alkaline 

 habitats. The collections (Table 1) made at these stations are of 

 interest not only because they include several new records for 

 the state but because of the isolated and restricted nature of the 

 outcrops. In spite of the widely separated localities and the dis- 

 tance to the nearest abundant limestone, four obligate calciphiles 

 were found. Of these, Asplenium resiliens appeared consistently 

 while Cheilanthes alahamensis was found at only two stations and 

 Asplenium cryptolepis and Carex plantaginea at one. In addition, 

 the calciphile, Cystopteris bulbifera, was found at three stations, 

 indicating its obligate nature under the extreme conditions. Several 

 other species with less positive alkaline predilections were rather 

 consistently present. 



The survey indicates that certain calciphiles tend to be present 

 wherever there is limestone, within or at the margins of their 

 ranges, even though the stations may be widely separated as in 

 North Carolina. Certain species not necessarily restricted to alka- 

 line habitats tend to become so when near the extremities of their 

 normal distribution. Of these species, apparently favored by a cal- 

 careous substratum where it is quite generally available, some 

 seem, here in North Carolina, to be concentrated in alkaline habitats 

 while others are apparently not affected in their numbers or dis- 

 tribution. 



Duke University, 

 Durham, N. C. 



^ Blomquist, H. L., and Correll, D. S. 1940. A county check list of North 

 Carolina ferns and fern allies. Jour. Elisha Mitchell Sci. Soc. 56 : 53-105. 



