Ecology and Management of Yellowflag Iris (Iris pseudacorus L.)

Invasive Species Technical Note Number MT-28

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Invasive Species Technical Note Number MT-28 (PDF; 138 KB)

August 2010

By Jim Jacobs, Invasive Species Specialist, NRCS, Bozeman, MT
Melissa Graves, Weeds Integrated Pest Management (IPM) Specialist, Montana State University
Jane Mangold, Extension Invasive Plant Specialist, Montana State University, Bozeman, MT

Abstract

Yellowflag iris is a long-lived perennial with showy yellow flowers, long sword-shaped leaves and a stout rhizome with black sap. (See Figure 1.) It reproduces both by seed and splitting rhizomes that are spread by water currents. It is invasive in riparian areas where it can form dense, persistent populations that limit the abundance of native species important to ecosystem function. It is unpalatable to livestock and wildlife. The management priority for Yellowflag iris is early detection and rapid response because management of well-established populations is costly and long-term. Control options are limited to digging and grubbing rhizomes or applications of glyphosate with an aquatic label.

Figure 1. Yellowflag iris flowers. Photo by Jane Mangold, Montana State University, Bozeman, Montana.

Identification

Plant Biology

• Life History, Habitat, Spread and Impacts

Management Alternatives

References

Bussuyt, B., B. DeFré and M. Hoffmann. 2005. Abundance and flowering success patterns in a short-term grazed grassland: early evidence of facilitation. Journal of Ecology 93: 1104-1114.

Schlüter, U. and R.M.M. Crawford. 2001. Long-term anoxia tolerance in leaves of Acorus calamus L. and Iris pseudacorus L. Journal of Experimental Botany. 52:2213-2225.

Sutherland, W.J. 1990. Biological flora of the British Isles. No. 169 Iris pseudacorus L. Journal of Ecology 78: 833-848.

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Last Modified: 11/10/2011