Although sometimes persistent after cultivation, this herb ("feverfew") may not be truly naturalized in Ky. The related species, T. balsamita L. ("costmary"), has also been reported from Ky. (BA), but probably from a planted source (M). T. parthenium has an ancient history of medicinal uses, with the sesquiterpene lactone "parthenolide" an active ingredient. There is recent evidence that this compound has "displays anti-inflammatory, redox-modulating, and epigenetic activities, as well as selective cytotoxicity towards cancer stem and progenitor cells" (Freund et al 2020).