80 



There remain seventeen species which are, according to the 

 manuals, calcicolous in habit. These are the species of particular 

 interest. The nine species marked ( + ), indicating best develop- 

 ment on alkaline substrata, show no significant correlation with 

 these special stations. Cheilanthes lanosa was found only once and 

 then was not on calcareous rock. It occurs in several stations in 

 western North Carolina, apparently quite remote from limestone. 

 This is also probably true of Caj-ex heterosperma. Of the species 

 found at two stations, Selaginella apoda can be of no significance 

 for it appears in moist, shaded situations throughout the state. 

 Aquilegia canadensis likewise appears sporadically with no apparent 

 calcareous connections. Mitella diphylla is less common and less 

 widespread but would not be classed as primarily calcicolous in 

 North Carolina. Although found at three calcareous localities 

 Botrychium virginianuin occurs in almost any damp hardwood 

 forest and Cheilanthes tomentosa, though by no means common, 

 may be expected on any kind of rocky blufif. The consistent occur- 

 rences of Asplenium trichomanes and Adiantuni pedatum suggest 

 a calcareous relationship for, although they may be found on shaded 

 rocky bluffs in all parts of western North Carolina they would 

 hardly be expected with such frequency. 



The list includes four calciphiles (*). Poly gala Senega was 

 found at only one station but, since it is relatively rare in the 

 state, this collection may be significant. The repeated appearances 

 of Camptosorus and Pellaea indicate their adaptation to alkalinity 

 for they are found only rarely elsewhere. Cystopteris bulbifera is 

 definitely an obligate calciphile in North Carolina for it is only 

 found on limestone. Nearer the center of its range, it may not 

 always be so. This situation agrees with observations made by 

 Pesola^ in Finland where, he concluded, calcicolous species become 

 more closely bound by specific habitat factors the nearer they 

 approach the limits of their range, or if they are subjected to ex- 

 tremes in growing conditions. 



Four species were found which are usually recognized as grow- 

 ing only in calcareous soils (obligate calciphiles**). Among these, 



" Pesola, V. A. 1928. Kalsiumkarbonaatti kasvimaantieteelisena teki jana 

 Suomessa. Ann. Soc. Zoolog.-Bot. Fennicae Vanamo 9(1): 1-246. n.v. (See 

 Wherry, Ecology 11:450-452, 1930). 



