The flower Tanacetum cinerariifolium (Figure) is one of about 30 species in the genus Chrysanthemum. Also known as the Dalmatian chrysanthemum, the dried flower heads of this particular species is useful as a source of pyrethrum extracts. The natural pyrethrum has been used to make several different insecticides, most notably permethrin. While physicians have used permethrin to treat pediculosis capitis and scabies for decades, tales of the chrysanthemum and its uses dates back much further.
Roman J. Flower Power. JAMA Dermatol. 2016;152(8):888. doi:10.1001/jamadermatol.2015.5636