Flowering Rush (Butomus umbellatus)
Flowering Rush (Butomus umbellatus)

Flowering Rush

Butomus umbellatus


  • Native to temperate Eurasia.
  • Emergent plant that grows along shorelines and wetlands or as a submergent plant in lakes and rivers.
  • May or may not produce flowers. Flowers are pink to white. Blooms from June to August.
  • Typically grows in shallow waters but can survive in water as deep as 6 meters.
  • Disperses by wind, water and humans through improper garden waste disposal, water based recreation and trading.
  • Known infestations in the Pend D’Oreille River in the state of Washington. Please report immediately if you suspect an infestation.

Consequences of invasion

  • Extremely aggressive, spreads quickly and displaces native shoreline vegetation.
  • Adversely impacts native fish species by forming dense stands.
  • Provides favourable habitat for invasive fish species such as small and large mouth bass, northern pike and walleye.
  • Dense infestations negatively impact recreational boating and other recreational activities.

Status in the CKISS region

Integrated pest management options

  • Do NOT plant Flowering Rush in your water gardens. Utilize an alternative such as western blue iris (Iris missouriensis).
  • Properly dispose of garden and yard waste by bagging and disposing of at your local landfill.
  • Aquatic invasives can be very difficult to manage once they establish in a system, so prevention is the best option for this species.

Additional resources