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Medusahead (Taeniatherum caput-medusae)

Medusahead Synonyms: Taeniatherum caput-medusae ssp. asperum, Taeniatherum asperum, Taeniatherum crinitum var. caput-medusae, Elymus caput-medusae

Common Names: Medusahead rye

Description: Severely destructive to rangelands across western and central United States. It was introduced to the United States in the late 1880s and spread rapidly in the 1930s.

Habit: Slender, annual grass reaching a height of 6-20 inches.

Leaves: Less than 1/8 in. (0.3 cm) wide, slender and somewhat rolled.

Stems: One or more stems arise from base of the plant. Can reach a height of 6-20 inches tall.

Flowers: Appear in late spring and are green in color. Flower heads develop at the apex of the stems.

Fruit and seeds: Each stem will produce a single seed head. Nodding spikes are dense bristly seed heads with long awns reaching 1-4 inches in length. Seed heads have 2 sets of bristles; shorter one extend at an angle, longer ones are erect. Each spikelet contains one seed and each seed head can produce more than 20 seeds.

Habitat: Native to the Mediterranean region. Found in dry, open lands with frequent disturbance.

Reproduction: Produces an extreme amount of viable seed, up to 6,000 seeds per square foot.

Similar species: Foxtail barley (Hordeum jubatum), which has long, numerous awns. Can be distinguished because its inflorenscence does not break apart upon maturity.

Monitoring and rapid response: Tillage is extremely effective. Till prior to flowering to prevent seed production. Multiple tillings may be required. Mowing prior to seed-set may also reduce coverage following year. Glyphosate and Imazapic applications can be effective along with prescribed fire.

Credits: The information provided in this factsheet was gathered from the Wisconsin Department of Natural Resources.

Individual species images that appear with a number in a black box are courtesy of the network ( photo author credits may not be included due to the small display size of the images and subsequent difficulty of reading the provided text. All other images appear courtesy of Google (

Common Name:


Scientific Name:

Taeniatherum caput-medusae







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