This annual originated in western North America, but has become a common weed in temperate regions around the world; see notes on its status in FNA 19. It was not recorded in Ky. by Anderson (1947), B or earlier botanists, but became widespread mostly after 1970; Although plants have an "pineapple" aroma that may be too strong for some human tastes (and appears to repel most herbivorous mammals), the species has had a long tradition of medicinal and herbal use by native Americans (Moermann 1980). The chemistry of Matricaria species and Chamaemelum are generally similar but with different proportions of distinctive ingredients; these include diverse terpenoids, flavonoids, spiroethers and coumarins such as herniarin and umbelliferone (Ma et al. 2007, Srivastava & Gupta 2015).).