Achillea ageratum, also known as sweet yarrow, sweet-Nancy, or sweet maudlin, is a flowering plant in the sunflower family, native to southern Europe (Spain, Portugal, France, Italy, Greece, Balkans). It is cultivated in many places for its pleasant fragrance and sparingly naturalized in a few places outside its native range. In the Middle Ages it was used as a strewing herb to repel insects such as moths, lice and ticks and spread a good smell in private rooms.