This aromatic annual ("tarweed") is centered in or near the Rocky Mts. but now also adventive from the northern plains to New England (Cr). In Ky. it has been recorded only from archaeological sites of the Fort Ancient era (1000-1500 A.D.), when it may have been used by native people (Henderson 1998). M. sativa Molina is a distinct species (2n = 32 versus 28) that should also be expected; it is widespread in North and South America, and "becoming widespread as a roadside weed" in eastern states (Cr).