This has been a common weed in eastern North America since early after settlement. In the central Bluegrass, Short (1828-9) noted: "abundant on the alluvion bottoms of our creeks and rivers, and in the fence-rows of rich, cultivated fields." Variation deserves more attention; 2n = 16 and 36. Most or all colls. from Ky. are referable to var. micrantha Moric. (F), which is not generally recognized in recent treatments (Cr, W). There has been much traditional use in Europe for medicine or even food, given its content of vitamin C and phenolic antioxidants (Barros et al. 2010, Milovanovic et al. 2010). However, its taste is generally considered too strong or disagreeable for pure consumption by humans, probably due to irritating terpenoids. Moreover, the plants may be generally avoided or even slightly toxic for herbivorous mammals, from rabbits to livestock: "Livestock can be poisoned by ground ivy, but most animals do not like the taste and avoid eating the plant. However, ground ivy ingested in large amounts either fresh or as hay is toxic to horses. Signs of poisoning include salivation, sweating, and difficulty breathing. Fatalities are rare" (OARDC 2020).