XIV. ADDITIONS AND CORRECTIONS TO THE LIST OF 



THE VASCULAR FLORA OF ALLEGHENY 



COUNTY, PA. 



Bv Otto E. Jenninos. 



Since the i)ublication in 1901 of "A Preliminary List of the Vas- 

 cular Flora of Allegheny County, Pennsylvania," ^ based mainly upon 

 material in the Pennsylvania Herbarium of the Carnegie Museum, a 

 considerable number of additional species have been found to occur 

 in the County and many of these s]iecies are now represented by 

 specimens in the Herbarium. 



A critical study of more abundant, or in some cases better material, 

 together with the examination of certain of the more difficult groups 

 by specialists, has brought to light a few errors in identification and 

 verified several doubtful reports. A number of the species enumerated 

 below were based only upon "reports" in the " Preliminary List," 

 but are now authenticated by specimens in the Herbarium collected 

 in the County. 



There are approximately 2,285 species in the vascular flora of Penn- 

 sylvania (Pteridophyta and Spermatophyta), and of this number Alle- 

 gheny County now has credited to it 991 species, represented by per- 

 haps thrice that number of carefully determined specimens collected 

 in Allegheny County. This number is being constantly increased 

 from the current collections of members of the Museum Staff and of 

 various enthusiastic local collectors as well as by a critical study of 

 older unidentified material which has in various ways come into the 

 possession of the Museum. 



In connection with many of the species mentioned in this list there 

 are given various notes and data of locality, relative abundance, etc., 

 such as might be of interest to local collectors. 



The following species were not reported in the " Preliminary List " 

 but have since been found to occur in the County and are now repre- 



' Shafer, J. A., " A Preliminary List o( the Vascular Flora of Allegheny County, 

 Pennsylvania," Annai.s Carnegie MrsKu.M, Vol. I., pp. 14-127, March, 1501. 



473 



