This alien diploid (2n = 16) winter-annual is scattered over northeastern states, especially in riparian or mesic woods along trails. Although present in North America as early as 1916, the species has been slow to spread. In Ky. it has been collected only since 1979, from CAMP (NCU, KNK), JEFF (MM for APSC) and LEWi (BEREA). It remains largely unknown in s. Ohio and s. Ind. (K). See also notes under flexuosa, which has been confused.