1. Invasive Plant Presentation: Medusahead Presented by: Annie Staehlin

2. The Basics  Taeniatherum 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

3. Description   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

5. Reproduction & 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

6. Geographic 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

7. 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

8. Invasive Because… 1. 1. Vacant niche 2. 2. Allelopathy 3. 3. Global climate change 4. 4. Resource Availability 5. 5. Competition 6. 6. Micro evolutionary changes 7. 7. Escape from biotic restraints 8. 8. Disturbance / land use 9. 9. Anthropogenic “Medusahead typically invades rangeland communities. Dense stands often develop, displacing desirable vegetation and wildlife, and lowering livestock carrying capacity”

9. Ecological 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

10. Management 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

11. References Bodurtha, 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.shtml http://www.cdfa.ca.gov/PHPPS/ipc/weedinfo/taeniatherum-caput-medusae.htm http://ucanr.org/delivers/impactview.cfm?impactnum=387