264 KERN: BERBERIS VULGARIS IN PENNSYLVANIA 
known to be thoroughly established. In any investigation of the 
distribution of this plant cognizance must be taken of the fact 
that it is still largely cultivated and that it exists also as an escape. 
I wish to deal chiefly with the latter phase in the present paper. 
No attempt is made here to present any conclusions regarding the 
connection of the barberry to the rust situation. 
By turning to the manuals or floras of the northeastern states 
it was not possible to form a very definite conception of the 
probable distribution of Berberis vulgaris as a wild plant of Penn- 
sylvania. Gray’s Manual states that it is to be found in ‘thickets 
and waste grounds in eastern and southern New England, where 
it has become thoroughly wild; elsewhere occasionally sponta- 
neous.” This did not indicate that it would likely be found at 
all common or thoroughly wild in Pennsylvania although our 
results have shown this to be the case. Britton & Brown’s 
“Illustrated Flora’’ gives the distribution as “‘ thickets, naturalized 
from Europe in the Eastern and Middle States, adventive in 
Canada and the west.”’ 
Among the more local publications one would turn first to 
Porter's Flora of Pennsylvania. Here distribution, as it was 
known to the author, is outlined by counties. Northampton, 
Franklin, and Susquehanna are listed under Berberis vulgaris. 
This was a definite beginning. Here were three counties in which 
this plant was known as an escape to Porter, some time during his 
botanical career, 1836-1901. Other local publications in the form 
of regional and county floras soon added additional localities, 
Dudley & Thurston’s Flora of the Lackawanna and Wyoming 
Valleys (1892) records one bush, west of Archbald, Lackawanna 
County, and one in a swamp near Kingston, Luzerne County. 
Twining’s Flora of Northeastern Pennsylvania (1917) reports B. 
vulgaris as ‘‘local; a pest near Waverly and Wallsville’”’ both in 
Lackawanna County. Fretz, in a Flora of Bucks County (1905). 
gives three stations, Bensalem, near Jericho Hill, and Doylestown. 
From the foregoing account it will be seen that, without an undue 
search of the coma definite information was obtained that 
the bar berry had been known as an escape in six Pennsylvania 
counties. Most of these reports were founded on observations 
made several years before and in order to know the present day 
