- any of various composite plants, as Pulicaria dysenterica, of Europe, or Erigeron philadelphicus, of the U.S., reputed to destroy or drive away fleas.
- any of several plants of the genus Erigeron, such as E. acer, having purplish tubular flower heads with orange centres: family Asteraceae (composites)
- any of several plants of the related genus Pulicaria, esp the Eurasian P. dysenterica, which has yellow daisy-like flower heads
- a related plant, Conyza (or Erigeron) canadensis, with small white tubular flower heads
- any of various other plants reputed to ward off fleas
