Keys to Identification
- An aggressive winter annual grass
- The 4 inch inflorescence persists after the plant has matured
Family: Grass (Poaceae)
Other Names: medusahead rye
USDA Code: TACA8
Legal Status: Colorado Noxious List A
Not yet found in Colorado.
Photo: Sue Donaldson, UNCE
Lifecycle: Winter annual
Growth form: Grass. 6-24 in 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.
Leaves: Slender, rolled, 1/8 in wide.
Stems: Slender, jointed.
Exotics: Seedlings similar to downy brome.
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.
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.
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.