INTRODUCTION 31 



and Schwalbea americana. There are perhaps others and it has 

 been suggested that these coastal plain species together with many 

 more that are also found on Long Island, have reached Con- 

 necticut via a land bridge that is supposed to have stretched from 

 Long Island to the Connecticut mainland in post-glacial times.* 

 That such an assumption is necessary seems doubtful. It is 

 easily understood how such coastal species found in Connecticut 

 and not on Long Island might have followed along the north side 

 of the Sound. 



50. One other extra-territorial occurrence of coastal plain species 

 should also be noted. Dr. N. L. Britton was the first to show that 

 there existed in northern New Jersey and adjacent New York a 

 small group of plants that are usually considered only coastal 

 plain or pine-barren species. | This paper has been widely quoted 

 as illustrating the distributional instability of some pine-barren 

 species, but careful reading of Dr. Britton's paper shows that all 

 the plants mentioned there, with one exception, are not pine- 

 barren plants, strictly speaking, at all. They are all merely 

 plants of the sandy coastal plain, Corema Conradii, a true pine- 

 barren plant, being the one exception. The distribution of this 

 species and of the many others now found isolated outside of the 

 pine-barrens or the coastal plain is to be sought in the post-glacial 

 history of the region to the north. In the general vegetative 

 scramble, so to speak, to cover the country uncovered by the 

 retreating ice, it seems natural that those plants whose ancestral 

 home had been in sand, should "choose" sand as a stopping place. 

 It would, in reality, be strange if they had done anything else, 

 and it is significant that all the plants mentioned by Britton are 

 sand plants. A list of those species that are found on the coastal 

 plain and in locally sandy areas in the Kittatinny mountains in 

 northwestern New Jersey and adjacent New York follows: 



Pinus rigida,% Polygonella articulata, 



Scleria panciflora, Cracca virginiana, 



Juncus Greenei, Lupinus perennis. 



* Hollick, A. Plant distribution as a factor in the interpretation of geological 

 phenomena, with special reference to Long Island and vicinity. Trans. N. Y. Acad. 

 Sci. 12: 189-202. 1893. 



t Britton, N. L. On the existence of a peculiar flora on the Kittatinny mountains 

 of northwestern New Jersey. Bull. Torrey Club II: 126-128. 1884, 14: 187. 1887. 



t Reported as making a more exclusive growth than it usually does in the north. 



