Ecology and Management of Flowering Rush (Butomus umbellatus L.)

Invasive Species Technical Note Number MT-33

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Invasive Species Technical Note Number MT-33 (PDF; 332 KB)

September 2011
By Jim Jacobs, Plant Materials Specialist, USDA-NRCS, Bozeman, Montana
Jane Mangold, Extension Invasive Plant Specialist, Montana State University, Bozeman, Montana
Hilary Parkinson, Research Associate, Montana State University, Bozeman, Montana
Virgil Dupuis, Salish Kootenai College, Pablo, MT
Peter Rice, Research Ecologist, University of Montana, Missoula, MT

Figure 1. Flowering rush restricting flow in an irrigation ditch in Lake County, Montana. Photo by Alvin Mitchell, Salish Kooteani College, Pablo, Montana.

Abstract

Flowering Rush is an invasive Eurasian aquatic plant resembling a large sedge with emerged and fully submerged forms and umbrella-shaped clusters of 20 to 50 light-pink to rose-colored flowers. The fleshy rhizomatous roots fragment by minor disturbances and spread populations long distance by floating on water currents. It grows along lake shores and slow moving bodies of water. In Montana it is currently reported along the shores of Flathead Lake, portions of the Flathead River, Thompson Falls Reservoir, Noxon Reservoir, Cabinet Gorge and the Clark Fork River. Dense populations growing within irrigation ditches reduce water availability and flow (see Figure 1), and dense populations along lake shores inhibit boating, fishing, and swimming. Control methods are currently limited to hand and mechanical digging and herbicide application after water drawdown (check local regulations before applying these managements). Chemical control method studies are ongoing. Prevention, early detection and rapid response to eradicate new populations are the management priorities for Montana. Consult your county weed coordinator for the best management options for your area. New populations should be reported to county Extension agents or weed coordinators.

Plant Biology

• Identification
• Life History
• Habitat
• Spread
• Impacts

Management Alternatives

• Prevention
• Mechanical Control
• Cultural Control
• Chemical Control
• Biological Control
• Integrated Pest Management (IPM)

References

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Boutwell, J.E. 1990. Flowering rush: A plant worth watching. Aquatics. 12: 8-11.

Brown, J.S. and C.G. Eckert. 2005. Evolutionary increase in sexual and clonal reproductive capacity during biological invasion in an aquatic plant Buomus umbellatus (Butomaceae). American Journal of Botany. 92: 495-502.

Cooper, J.E., J.V. Mead, J.M. Farrell, and R.G. Werner. 2008. Potential effects of spawning habitat changes on the segregation of northern pike (Esox lucius) and muskellunge (E. masquinongy) in the upper St. Lawrence River. Hydrobiologia. 601: 43-53.

Eckert, C.G., B. Massonnet, and J.J. Thomas. 2000. Variation in sexual and clonal reproduction among introduced populations of flowering rush, Butomus umbellatus (Butomaceae). Canadian Journal of Botany-Revue Canadienne De Botanique. 78: 437-446.

Fritts, A.L. and T.N. Pearsons. 2004. Smallmouth bass predation on hatchery and wild salmonids in the Yakima River, Washington. Transactions of the American Fisheries Society. 133: 880-895.

Hunter, C. 1991. Better trout habitat: A guide to stream restoration and management. Montana Land Reliance. Island Press, Washington D.C.

Hroudova, Z. 1989. Growth of Butomus umbellatus at a stable water level. Folia Geobotanica Et Phytotaxonomica. 24: 371-385.

Hroudova, Z. and P. Zakravsky. 2003. Germination responses of diploid Butomus umbellatus to light, temperature and flooding. Flora. 198: 37-44.

Hroudova, Z., A. Krahulcova, P. Zakravsky, and V. Jarolimova. 1996. The biology of Butomus umbellatus in shallow waters with fluctuating water level. Hydrobiologia. 340: 27-30.

Lui, K., F.L. Thompson, and C.G. Eckert. 2005. Causes and consequences of extreme variation in reproductive strategy and vegetative growth among invasive populations of a clonal aquatic plant, Butomus umbellatus L. (Butomaceae). Biological Invasions. 7: 427-444.

Madsen, J.D. and J.C. Cheshier. 2009. Eurasian watermilfoil survey of three reservoirs in the lower Clark Fork River, Montana: I. Results of the field vegetation survey: Geosystems Research Institute Mississippi State University. GRI Report #5033. 59p.

Muhlfeld, C.C., D.H. Bennett, R.K. Steinhorst, B. Marotz, and M. Boyer. 2008. Using bioenergetics modeling to estimate consumption of native juvenile salmonids by nonnative northern pike in the upper Flathead River system, Montana. North American Journal of Fisheries Management. 28: 636-648.

Perers, W.L., M.H. Meyer, and N.O. Anderson. 2006. Minnesota horticultural industry survey on invasive plants. Euphytica. 148: 75-86.

Rice, P. INVADERS database System. Division of Biological Sciences, University of Montana, Missoula, Montana. http://invader.dbs.umt.edu.

Rice, P. and V. Dupuis. 2009. Flowering rush: and invasive aquatic macrophyte infesting the headwaters of the Columbia River system. Available at Center for Invasive Plant Management (CIPM). http://www.weedcenter.org/projects-spatial.html.

Tabor, R.A., R.S. Shively, and T.P. Poe. 1993. Predation on juvenile salmonids by smallmouth bass and northern squawfish in the Columbia River near Richland, Washington. North American Journal of Fisheries Management. 13: 831-838.

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Last Modified: 11/10/2011