140 Cincinnati Society of Natural History. 



Baldwinii : East Missouri (West Tennessee) to Texas. 



altissima : West Pennsylvania to Illinois, Louisiana and 

 Florida. 



var. grandiflora: Illinois and Kentucky to Texas. 



fasciculata : General, but mostly central. 



oligophylla : North Carolina to Florida. 

 A last peculiar feature of the genus, and one that adds to its 

 difficulty, is the occasional occurrence of natural hybrids between 

 several distinct species. These have not been fully investigated, 

 and the only mention found of them is in the " Synoptical Flora." 

 Here it is stated that hybrids between Arkansana and Baldwinii, ' 

 between fasciculata and Baldwinii and between Lindheimeri and 

 Baldwinii have been found. The last was collected by Berlandier. 

 May it not be that Baldwinii is itself a hybrid ? 



