In North America, this alien rhizomatous diploid (2n = 16) occurs mostly in northern regions, and rare southern plants are probably just waifs. It is close to sylvestris, and hybrids may be expected (Rollins 1993). The only record from Ky., or perhaps anywhere else in the Ohio Valley (PL), is a verified coll. from CAMP (KNK): J.W. Thieret #48934, 4 Jun 1976, roadside along highway US 27 directly across from entrance to NKU campus, Highland Heights.