Garlic Mustard in the U.S.A.

[John V. Calhoun]

Just an interesting tidbit that may be of interest. Regarding the 
species of garlic mustard in North America, it is Alliaria officinalis 
(naturalized from Europe). The original question referred to whether our 
species is A. petiolata, which is a different Old World species.  
According to my reference books, there are at least five species of 
Alliaria, native to Europe and Asia.  Alliaria officinalis has been in 
this country since at least the turn of the century, probably much 
longer.  
It will be interesting to see how A. officinalis continues to affect 
populations of P. virginiensis.  The plant doesn't occur in Florida 
(hopefully it never will). But then we don't have to worry much about 
populations of P. virginiensis being bothered here (since it doesn't 
occur within hundreds of miles of Florida).  However, we have recently 
located potential populations of Paramidea midea in the central 
panhandle.  Perhaps this could become a future concern for this species 
if Alliaria adapts to this climate.      

Best,
John Calhoun