medusahead USDA PLANTS Symbol: TACA8
U.S. Nativity: Exotic
Habit: Grass or Grasslike
Taeniatherum caput-medusae (L.) Nevski

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Taxonomic Rank: Liliopsida: Cyperales: Poaceae
Synonym(s): medusahead rye
Native Range: Africa, temp. & trop Asia, Europe (GRIN);

Appearance
Taeniatherum caput-medusa is an annual grass that is 8-24 in. (20.3-61 cm) tall and has distinct bristly seed heads and few leaves.
Foliage
Leaves are less than 0.13 in. (0.32 cm) wide. One or more stems arise from the base of the plant and can be as much as 2 ft. (0.6 m) tall. Each stem produces a single, short, spike-type seed head.
Flowers
Flowering occurs in late spring, when flower heads develop at the apex of the stems. Flowering occurs in late spring and early summer.
Fruit
The seed heads are what distinguish this plant from other annual grasses. Awns twist as they dry, hence the common name "medusahead". The longer of the two awns in each spikelet is barbed. These barbs catch on fur or clothing and spread seed.
Ecological Threat
T. caput-medusa was first collected in Oregon, in 1887. Plants invade dry, open lands with frequent disturbance such as fields and pastures. It is native to the Mediterranean.

Identification, Biology, Control and Management Resources

Selected Images from Invasive.orgView All Images at Invasive.org


Control; burning
Steve Dewey, Utah State University, Bugwood.org
Additional Resolutions & Image Usage

Fruit(s);
Steve Dewey, Utah State University, Bugwood.org
Additional Resolutions & Image Usage

Infestation;
Steve Dewey, Utah State University, Bugwood.org
Additional Resolutions & Image Usage

Plant(s);
Steve Dewey, Utah State University, Bugwood.org
Additional Resolutions & Image Usage

Fruit(s);
Steve Dewey, Utah State University, Bugwood.org
Additional Resolutions & Image Usage

Infestation;
Steve Dewey, Utah State University, Bugwood.org
Additional Resolutions & Image Usage

Prescribed Fire;
Steve Dewey, Utah State University, Bugwood.org
Additional Resolutions & Image Usage

Feature(s); Medusahead on left, cheatgrass on right
Steve Dewey, Utah State University, Bugwood.org
Additional Resolutions & Image Usage

Flower(s);
Chris Evans, University of Illinois, Bugwood.org
Additional Resolutions & Image Usage

Diagram or Graphic; Hitchcock, A.S. (rev. A. Chase). 1950. Manual of the grasses of the United States. USDA Misc. Publ. No. 200. Washington, DC.
USDA PLANTS Database, USDA NRCS PLANTS Database, Bugwood.org
Additional Resolutions & Image Usage

Fruit(s);
Steve Hurst, USDA NRCS PLANTS Database, Bugwood.org
Additional Resolutions & Image Usage

EDDMapS Distribution:
This map is incomplete and is based only on current site and county level reports made by experts and records obtained from USDA Plants Database. For more information, visit www.eddmaps.org
 


State(s) Where Reported invasive.
Based on state level agency and organization lists of invasive plants from WeedUS database.


Invasive Listing Sources:
California Invasive Plant Council
Faith Campbell, 1998
John Randall, The Nature Conservancy, Survey of TNC Preserves, 1995.
Native Plant Society of Oregon, 2008
Pacific Northwest Exotic Pest Plant Council, 1998