Medusahead
Taeniatherum caput-medusae
Keys to Identification
- An aggressive winter annual grass
- The 4 inch inflorescence persists after the plant has matured
Family: Poaceae (Grass)
Other Names: medusahead rye
USDA Code: TACA8
Legal Status: Colorado Noxious List A
Not yet found in Colorado.
Photo: Sue Donaldson, UNCE
Identification
Lifecycle: Winter annual
Growth form: Grass. 6-24 inches tall. Germinates in fall. Matures later than other annuals.
Inflorescence: Long-awned spike. Head persists after seed fall. Awns are twisted, stiff when mature. May-June.
Seeds/Fruit: Awned-floret
Leaves: Slender, rolled, 1/8 in wide
Stems: Slender, jointed.
Roots: Fibrous
Seedling: Yellow-green
Similar Species
Exotics: Seedlings similar to downy brome
Impacts
Agricultural: Unpalatable to livestock when mature. Aggressive. Degrades rangelands. Builds up duff layer that ties up nutrients and may contribute to fire
Ecological: Degrades natural lands
Habitat and Distribution
General requirements: Semi-arid clay soils
Distribution: Western US
Historical: Native to Mediterranean region
Biology/Ecology
Life cycle: Annual
Mode of reproduction: Seed
Dispersal: Animal, wind, water
Integrated Management Summary
Burning will remove the thick duff layer.
Early grazing may provide some control.
Herbicide treatments are most effective.
References
Maurer, T., Russo M. J. (Revision), Godell A. (Revision); ELEMENT STEWARDSHIP ABSTRACT for Taeniatherum caput-medusae; http://tncweeds.ucdavis.edu/esadocs/documnts/taencap.pdf
The PLANTS Database, database (version 5.1.1) 2000; National Plant Data Center, NRCS, USDA. Baton Rouge, LA 70874-4490 USA. http://plants.usda.gov Reference for: Taeniatherum caput-medusae
Whitson, T.D.(ed.), L.C. Burrill, S.A. Dewey, D.W. Cudney, B.E. Nelson, R.D. Lee, R. Parker. 2001. Weeds of the West. Western Society of Weed Science, in cooperation with the Western United States Land Grant Universities Cooperative Extension Services, Newark CA. pg. 493.
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