Fleabane (Erigeron species) is a member of the aster family with small, highly engaging daisylike flowers. Depending on species and variety, the flowers may range in color from white to pink to purple and the plant may reach a foot to three feet tall and be annual, biennial, or half-hardy perennial. The common name comes, of course, from the long-held belief that the oil of the plant repels fleas, a claim that evidently has not been scientifically proven.