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Species Profiles



Scientific name: Taeniatherum caput-medusae (L.) Nevski (ITIS)

Synonyms: Elymus caput-medusae L.; Taeniatherum asperum(Simonkai) Nevski; Hordeum caput-medusae (L.) Crosson & Durand (ITIS)

Common names: Medusahead, medusa's head, medusahead rye, medusahead grass

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Selected Resources

Native To: Mediterranean Region (Archer 2001)

Date of U.S. Introduction: First discovered in 1887 (DiTomaso et al. 2008)

Means of Introduction: Introduced as a seed contaminant (DiTomaso et al. 2008)

Impact: Crowds out native species and forage for livestock (Archer 2001)

Current U.S. Distribution:



Selected Resources:

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Council or Task Force

Invasive Plants of California's Wildlands - Taeniatherum caput-medusae
California Invasive Plant Council.
In online book: Bossard, C.C., J.M. Randall, and M.C. Hoshovsky (Editors). 2000. Invasive Plants of California's Wildlands. University of California Press. Berkeley, CA

Fact Sheet: Medusahead (Jan 2014; PDF | 752 KB)
Alberta Invasive Plant Council (Canada).
See also: Fact Sheets for more information about individual invasive species, including those listed as "Prohibited Noxious" and "Noxious" under the Alberta Weed Control Act


Invasive Plant Atlas of the United States - Medusahead
University of Georgia. Center for Invasive Species and Ecosystem Health.

Invasive Species Compendium - Taeniatherum caput-medusae
CAB International.

Federal Government

U.S. National Plant Germplasm System - Taeniatherum caput-medusae
USDA. ARS. National Genetic Resources Program. GRIN-Global.

Fire Effects Information System (FEIS) - Taeniatherum caput-medusae
USDA. FS. Rocky Mountain Research Station. Fire Sciences Laboratory.

PLANTS Database - Medusahead
USDA. NRCS. National Plant Data Center.

State Government

Encycloweedia: Data Sheet - Medusahead
California Department of Food and Agriculture.
Included on California's noxious weed list; see Encycloweedia: Program Details for additional resources.

Medusahead (PDF | 183 KB)
State of California. Plumas-Sierra Noxious Weeds Management Group.

Noxious Weed Species - Medusahead
Colorado Department of Agriculture. Conservation Services Division. Noxious Weed Program.

Wisconsin Department of Natural Resources.


Weed Control in Natural Areas in the Western United States: Medusahead (2013; PDF | 204 KB)
University of California. Weed Research and Information Center.

Medusahead Management Guide for the Western United States (2014; PDF | 6.17 MB)
University of California. Weed Research and Information Center.

Medusahead rye - The Great Basin and Invasive Weeds
Utah State University.

Washington State University. Whitman County Extension.


Noxious Weed Information - Medusahead (A List)
Colorado Weed Management Association.

Wallowa County Weed Watch: Medusahead Rye (PDF | 187 KB)
Wallowa Resources (Oregon).


Archer, A.J. 2001. Taeniatherum caput-medusae. In: Fire Effects Information System. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory.

Integrated Taxonomic Information System. Taeniatherum caput-medusae. [Accessed Sep 10, 2014].

DiTomaso, J.M., G.B. Kyser, M.R. George, M.P. Doran, and E.A. Laca. 2008. Control of medusahead (Taeniatherum caput-medusae) using timely sheep grazing. Invasive Plant Science and Management 1(3):241-247.

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Last Modified: Sep 29, 2016
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