• 9 



82 Lloyd and Tracy : The insular Flora 



* 



salt water, make possible the growth of a large number of plants 

 characteristic of the austro-riparian. These plains present the 

 appearance of the typical pine barrens, with the absence of 

 magnolias and deciduous oaks. The trees are Pinus Taeda, P. 

 palustris, Quercus geminata and, less frequently, Q. Virgi 

 As woody undergrowth Sabal glabra, Serenoa semdata and a 

 large congeries of herbaceous plants common to the austroriparian. 

 In this regard the larger of the Delta islands stand in contrast with 

 Ocracoke. A few of the genera may be mentioned as indicating 

 the type of vegetation : Aristida, Ascyrum, Andropogon, Drosera, 



rerardia, Hypericum, Lacinaria, Leehea, Opuntia, 

 Panieum, Polygala, Rliexia, Sabbatia, Willughbaea. 



2. Certain plants are distributed far to the north and are found 



Heli 



as strand plants. 

 * Baptisia leucantha. 

 Cenchrus tribuloides. 

 Eclipta alba. 



Euphorbia polyg onifolia 



Ruppia maritima(\r 

 * Smilax Bona-nox. 

 Strophostyles helvol 



(Maryl 



monarda.punctata. Triplasis (Sieglingia) purpurea. 



Rhus copallina. Vitis aestivalis. 



Moseley has shown that the appearance of a certain number of 

 plants of southern distribution in the region of Sandusky Bay, 

 Lake Erie, is due to the higher temperature and longer growing 



A 



climate of Buffalo is noticed. Those plants marked thus * in the 

 above list occur also at Sandusky Bay. 



The following are found in North America only on the Atlantic 

 coast as far north as indicated. 

 Baccharis halimifolia (Mass.). 

 Borrichia f rule see ns (Va.). 

 Croton mari tii nus (N. C). 



Distichlis spicata 



(M 



Ilex vomitoria- (N . C; Va.?). 

 Iva f rut esc ens (Mass.). 

 June us scirpoides (N. Y.). 

 Kosteletskya Virgin ic a (N. Y 



Herculis(N. C; Va 



