Flowering Rush

Butomus umbellatus

Flowering Rush flower closeup.JPG
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Flower Rush infest.webp

Flowering Rush - An emergent invasive with a very limited distribution in Washington state that can sometimes stay submerged. Can grow up to 5 feet tall.

Leaves: - Thin upward growing leaves that often twist when above the surface of the water and reach 3+ feet in length (when plant is emerged and much longer when it is submerged). Leaves have a triangular cross section.

Flowers: - Blooms June - September with umbrella shaped clusters of 20-50 flowers that have 3 sepals and three white to deep purple petals.

Habitat: - Can appear in a variety of habitats and is often found in areas with shallow and fluctuating water levels such as along shorelines, wetlands, lakes and irrigation canals.

Weed Classification: A

Why is it a Noxious Weed?
It spreads via seeds, rhizomes and bulbs. Flowering rush has the potential to dominate an environment once established, forming dense monocultures and displacing native vegetation. At high densities, this plant may form a mat of plants which can separate from the root system and float on the surface accumulating sediment and filling in shallow margins of lakes or wetlands.

There is no known presence of Flowering Rush in Lewis County. If spotted, it should be reported to the Noxious Weed Control Program immediately.

Control Recommendations:
WA State Noxious Weed Board
UC Davis Treatment Options
Ontario Invasive Plants - Best Management Practices