Feverfew, a carefree perennial. Chrysanthemum parthenium or Tanacetum parthenium, a European species naturalized in the U.S., formerly cultivated as a medicinal herb.
Some ornamental varieties are common in gardens.
Rarely and improperly called wild chamomile because of its small flowers and yellow centers, says National Garden Association's Dictionary of Horticulture. Masses of small daisies on and off late spring to early winter. Single and double forms with yellow or white flowers. Reseeds self readily. Hardy to Zone 5.