Invasive Species: Flowering Rush

Flowering Rush

(Butomus umbellatus)
*Established in Michigan*

RESTRICTED IN MICHIGAN

Identification:

• Resembles a large sedge.
• May grow with upright foliage in shallow water or submerged with flexible leaves suspended in deeper waters.
• Leaves have triangular cross section, are narrow, and twist toward the tip.
• When flowering: flowers grow in round umbrella-like clusters of 20-50 flowers, 6 light pink to rose-colored petals per flower, 9 stamens per flower.
• Difficult to identify when not flowering.

Photo courtesy of Leslie J. Mehrhoff, University of Connecticut, Bugwood.org.

Flowering rush root and stems. Photo courtesy of Leslie J. Mehrhoff, University of Connecticut, Bugwood.org. 

Habitat: This perennial, aquatic, herbaceous plant typically grows in shallow sections of slow moving streams or rivers, lake shores, irrigation ditches and wetlands, although it can survive in very clear water up to 20 feet deep.

Native Range: Europe and Asia.

U.S. Distribution: Most of the northern contiguous U.S.

Local Concern: Flowering rush out-competes native species for resources and can hinder recreational activities like boating.

MORE INFORMATION:

• Flowering Rush Invasive Species Alert - Printable PDF
• Status and Strategy for Flowering Rush Management This document provides in-depth information about flowering rush in Michigan including identification, distribution, management and control options.
• MDARD Weed Risk Assessment for Flowering Rush (Butomus umbellatus) This document evaluates the invasive potential of the plant species using information based on establishment, spread and potential to cause harm.