This is now about as widespread as latifolia in eastern North America, but it may have spread during the post-Columbian era from Atlantic coastal regions or even Eurasia (FNA 22, W). It is considered more tolerant of alkaline or saline conditions, and it has increased inland during the past 50-100 years, especially along winter-salted interstates. It was first documented in Ky. during the 1930s (B).