Synonyms: Taeniatherum caput-medusae
Common names: medusahead
Elymus caput-medusae (medusahead) is a winter annual (family Poaceae) that typically invades disturbed sites, grasslands, openings in chaparral and oak woodlands. Medusahead out-competes native grasses and forbs and is found throughout northwestern California. After they set seed, medusahead plants persist as a dense litter layer that prevents germination and survival of native species, ties up nutrients, and contributes to fire danger in the summer.Cal-IPC Rating: High?
CDFA Rating: -*?
Plant Assessment Form - Information gathered by Cal-IPC on the impacts, rate of spread, and distribution of invasive plants in California. Does not include management information.
Species ID Card
Invasive Species ID Card - To support field identification of early detection species, Cal-IPC has designed a set of Species ID cards that can be downloaded, printed double-sided, and trimmed to size.
Special ReportsMedusahead Management Guide for the Western States
Weed Management Notes
- Management Notes - Information on management techniques and effectiveness from the University of California Cooperative Extension’s Weed Research & Information Center.
Cal-IPC Newsletter Articles
- Weed worker legend Joe DiTomaso retires. Brusati, Elizabeth. Vol 25, Issue 2
- One Tam unites around Marin’s mountain. Kesel, Rachel. Vol 24, Issue 3
- Native soil bacteria as biocontrol. Bean, Travis; Gornish, Elise. Vol 24, Issue 2
- Wildland Weed News. Cal-IPC. Vol 22, Issue 3
- Prescribed grazing for invasive plant control on rangelands. Davy, Josh; Tate, Kenneth; Roche, Leslie. Vol 21, Issue 3
- Impacts of native vs. exotic grassland vegetation. Eviner, Valerie; Heraty, Joanne; Baty, Jill; Malmstrom, Carolyn; Rice, Kevin. Vol 21, Issue 3
- Partnering with college helps track medusahead. Alford, Jim; Benedetti, Daniel; Jennings, Nathan. Vol 20, Issue 3
- Jepson Manual 2nd ed. invasive plant name changes. Brusati, Elizabeth. Vol 20, Issue 2
- Exploring alternative methods for vegetation control and maintenance along roadsides. Young, Steve L.. Vol 10, Issue 4
Cal-IPC Symposium Presentations
Presentations are linked where available. Where a presentation is not available, find more information by reading the abstract in the Cal-IPC Symposia Archive.
- Prescription fire for medusahead (Elymus caput-medusae) control and impacts to species composition in an invaded California grassland. Mills, Jason (2023)
- Expanding the use of prescribed fire as an ecosystem stewardship tool in fire-adapted landscapes. Lopez, Hannah (2022)
- Update on recent biological control releases against invasive plants by the USDA-ARS. Moran, Patrick; Pratt, Paul; Smith, Lincoln (2022)
- Winter annual grass control: experiences with Indaziflam in NE California. Getts, Tom (2022)
- Understanding herbicide labels and drones better. Miller, Beau (2021)
- Utilizing pathways of invader dominance to identify natives of concern. LaForgia, Marina (2021)
- Can tree and vine herbicide be effective for medusahead? Getts, Tom (2020)
- Evaluating control of late-season noxious grassland invasives with multiple approaches: wildfire, prescribed fire, native grass restoration, and organic herbicides. Eviner, Valerie (2020)
- Mapping weeds and rare plants to inform management and conservation in the Zaca and Jesusita fires. Calloway, Stephanie; Schneider, Heather; Knapp, Denise (2018)
- Recent research on invasive weeds at the European Biological Control Laboratory (EBCL). Smith, Lincoln; Bon, Marie-Claude; Desurmont, Gaylord; Kashefi, Javid; Sforza, René; Tannières, Mélanie; Cristofaro, Massimo; Marini, Francesca; Goolsby, John; Rector, Brian; Vidovic, Biljana; Winkler, Daniel; Moran, Patrick (2018)
- Revegetating medusahead (Taeniatherum caput medusae)-invaded rangeland. Nafus, Aleta; Davies, Kirk (2018)
- Grassland restoration and invasive weed management in Southern California: Medusahead as a case study. McDonald, Chris (2017)
- Plant community responses to cattle grazing in a noxious weed-dominated rangeland. Roche, Leslie; Tate, Ken (2016)
Other Elymus caput-medusae Information
- Bugwood - National database from the Center for Invasive Species and Ecosystem Health at the University of Georgia.
- CalPhotos - Images of plants taken mostly in California.
- Calflora - Distribution map and records of this species in California.
- EDDMapS - Distribution of this species in North America.
- Jepson Interchange - Information on this plant's taxonomy, biology, and distribution from UC Berkeley's Jepson Herbarium.
- USDA PLANTS Database - Information on identification and distribution, with links to websites in individual states.