Invasive Plant Presentation: Invasive Plant Presentation: MedusaheadMedusahead

Presented by: Annie StaehlinPresented by: Annie Staehlin

The BasicsThe Basics Taeniatherum caput-medusaeTaeniatherum caput-medusae Common names: medusahead,

Medusa’s head, medusahead rye, medusahead grass

Kingdom: Plantae Subkingdom: Tracheobionta Superdivision: Spermatophyta Division: Magnoliophyta Class: Liliopsida Subclass: Commelinidae Order: Cyperales Family: Poaceae Genus: Taeniatherum Nevski

DescriptionDescription Slender grass Winter annual Matures 2-4 weeks later Clay soils = BEST! Blooms May – June 6-18” tall Densely crowded bristly spike

1-4” long Rolled leaf blades 1/16” wide Very prickly “OUCH!” Fibrous roots grow throughout

the cool season

Spikelets: 2 per node Florets: 2 per spikelet

Reproduction & DispersalReproduction & Dispersal Reproduces by seed Prolific Dispersal through: wind, water, soil movement, human and animal

activities Rapid germination Broad temperature range Most seeds germinate in the fall Can germinate during winter or spring Can germinate under low moisture conditions

Geographic DistributionGeographic Distribution Native to Eurasia

especially the Mediterranean region

1880s: Introduced to the United States

Introduced accidentally as a seed contaminant

Currently found in 10 U.S. states: (CA, CT, ID, MY, NV, NY, OR, PA, UT, WA)

Habitat: Disturbed sites, grassland, openings in chaparral, oak woodlands, agronomic fields

Loves clayey soils

Invasive Because…Invasive Because… 11 - 15% silica Most grasses: 1 - 3% Fast growing roots Deplete upper soil moisture

and then access deep soil moisture during the growing season

Adapted for survival on vertisols

Early establishment Rapid germination Mature plants unpalatable to

grazing animals

Senesced form dense litter layer

Slow decomposition = temperature and moisture altered in soil

Fuel for wildfires

Invasive Because…Invasive Because…

1. Vacant niche2. Allelopathy3. Global climate change4. Resource Availability5. Competition6. Micro evolutionary

changes7. Escape from biotic

restraints8. Disturbance / land use9. Anthropogenic

““Medusahead Medusahead typically invades typically invades rangeland rangeland communities. communities. Dense stands often Dense stands often develop, displacing develop, displacing desirable vegetation desirable vegetation and wildlife, and and wildlife, and lowering livestock lowering livestock carrying capacity”carrying capacity”

Ecological and Social ImpactsEcological and Social Impacts Social:

Reduction of quality and yield of livestock forage 75% reduction in grazing capacity Rural economy and agricultural industry

Ecological: Reduction of quality and yield of livestock forage Decrease in species diversity and species richness Young forage is food for grazers

Management StrategiesManagement Strategies Prevention:

controlled winter and spring grazing restoration and management work together

Mechanical: tillage for seedbed preparation mowing

Biological: soil fungi

Chemical: Glyphosphate and paraquat Atrazine

Fire: Soil seedbank Plant community recovery time

ReferencesReferencesBodurtha, T.S., J.P. Peek, Lauer, J.L. 1989. Mule deer habitat use related to succession in a bunchgrass community. Journal

of Wildlife Management 53:314-319.Bovey, R. W., LeTourneau, D., and Erickson, L. C. 1961. The chemical composition of medusahead and downy brome. Weeds

9:307-311.Brannon, T. A. 1972. Some interaction between nitrate nitrogen and temperature in portions of the life cycle in four range

grasses. 69p. Thesis. Washington State University.Dahl, B. E. and Tisdale, E. W. 1975. Environmental factors related to medusahead distribution. Journal of Range Management

28:463-468.Evans, R. A. and Young, J. A. 1985. Plant succession following control of western juniper (Juniperus occidentalis) with

picloram. Weed Science 33:63-68.Fosberg, M. A. 1965. Relationship of cheatgrass and medusahead to soils in the Colombia River Basin. Proceedings of the

Cheatgrass Symposium Vale, OR. U.S. Dept. of the Interior, Bureau of Land Management, Washington, D.C.Frederiksen, S. 1986. Revision of Taenaiatherum (Poaceae). Nordic Journal of Botany 6:389-397.Furbish, P. 1953. Control of medusahead on California ranges. Journal of Forestry 51:118-121.George, M.R., R.S. Knight, P.B. Sand, and N.W. Demment. 1989. Intensive grazing management on annual range. California

Agriculture 43:16-19.Goebel, C. J., Tazi, M., and Harris, G. A. 1988. Secar bluebunch wheatgrass as a competitor to medusahead. Journal of Range

Management 41:88-89.Hilken, T.O., and R.F. Miller. 1980. Medusahead (Taeniatherum asperum): A review and annotated bibliography. Agricultural

Experiment Station Bulletin 644, Oregon State University, Corvallis. Lusk, W.C., M.B. Jones, D.T. Torell, and C.M. McKell. 1961. Medusahead palatability. Journal Range Management 14:248-251.Major, J., C.M. McKell, and L.J. Berry. 1960. Improvement of medusahead-infested rangeland. University of California

Agricultural Experiment Station. Leaflet 123. 6p.McKell, C.M., A.M. Wilson, and B.L. Kay. 1962. Effective burning of rangelands infested with medusahead. Weeds 10:125-131.Miller, H. C., D. Clausnitzer, and M. M. Borman. 1999. Medusahead. In: R.L. Sheley and J.K. Petroff [EDS.]. Biology and

management of noxious rangeland weeds. Corvallis, OR: Oregon State University Press. p. 271-281.http://www.invasivespeciesinfo.gov/plants/medusahead.shtmlhttp://www.cdfa.ca.gov/PHPPS/ipc/weedinfo/taeniatherum-caput-medusae.htmhttp://ucanr.org/delivers/impactview.cfm?impactnum=387