1. Torpedograss Panicum repens (L.) Poaceae

2. Biology Native to Africa and or AsiaNative to Africa and or Asia Introduced into Florida in late 1800’s as a wetland forage grassIntroduced into Florida in late 1800’s as a wetland forage grass Perennial, spreads through stolons and rhizomesPerennial, spreads through stolons and rhizomes Named for sharply pointed or ‘torpedo- like’ growing tipsNamed for sharply pointed or ‘torpedo- like’ growing tips

3. Background Economic Uses Cultivated as wetland forageCultivated as wetland forage Fast growth and high productivityFast growth and high productivity Readily grazed by cattleReadily grazed by cattle

4. Distribution Found throughout much of north, central and south FloridaFound throughout much of north, central and south Florida Commonly found along waterways including canals, irrigation/drainage ditches and low, wet areasCommonly found along waterways including canals, irrigation/drainage ditches and low, wet areas Over 7000 acres in Lake OkeechobeeOver 7000 acres in Lake Okeechobee

5. Torpedograss Distribution in Florida

6. Impacts Category 1 invasive species (FLEPPC)Category 1 invasive species (FLEPPC) –Very aggressive spread into undisturbed sites, over 70% of public waters are infested Strong competitor, forms large floating mats, impeding water flow and navigation and recreationStrong competitor, forms large floating mats, impeding water flow and navigation and recreation Displaces native species – flora & faunaDisplaces native species – flora & fauna Also a major problem in citrus and turfAlso a major problem in citrus and turf

7. Identification

8. Mature Plant Perennial grass, roots on shore and will extend several feet out into shallow waterPerennial grass, roots on shore and will extend several feet out into shallow water Will grow up thru the water columnWill grow up thru the water column Forms dense monoculture along shoreline of lakes and pondsForms dense monoculture along shoreline of lakes and ponds

9. Leaves Leaf blades are 2 to 4 inches long, ¼ inch wide, stiff and foldedLeaf blades are 2 to 4 inches long, ¼ inch wide, stiff and folded Bluish green colorBluish green color Hairy on upper leaf surfaceHairy on upper leaf surface

10. Rhizome Rhizomes arise from swollen crown tissue (knuckles)Rhizomes arise from swollen crown tissue (knuckles) Rhizomes are very extensive, can comprise over 90% of total plant biomassRhizomes are very extensive, can comprise over 90% of total plant biomass Sharp, torpedo-like tipsSharp, torpedo-like tips

11. Panicle Up to 9 inches long, numerous branchesUp to 9 inches long, numerous branches Reported poor seed viabilityReported poor seed viability

12. Management PreventativeCulturalMechanicalBiologicalChemical

13. Preventative 1.Limit planting as a forage 2.Remove existing plants, including stolons and rhizomes before seeds are produced 3.Prevent movement of plant material into areas not infested with torpedograss

14. Cultural 1.Cattle grazing will often keep in check, but to a limited extent 2.Programs to educate farmers and ranches about the problems associated with torpedograss and proper identification

15. Biological 1.There are no known biological control agents available for torpedograss management (with the exception of grazing) in Florida or the southeastern U.S.

16. Mechanical 1.Small infestations can be removed with repeated, aggressive tillage  Limited to non-flooded sites 2.Burning effective in removing above ground biomass, may enhance chemical control measures

17. Chemical 1.Broadcast applications for large areas Glyphosate at 2 to 4 lbs-ai/A Glyphosate at 2 to 4 lbs-ai/A Imazapyr at 0.5 to 1.0 lbs-ai/A Imazapyr at 0.5 to 1.0 lbs-ai/A 2.Spot treatment for smaller areas Glyphosate – 2 to 3% solution Glyphosate – 2 to 3% solution Imazapyr – 0.5 to 1% solution Imazapyr – 0.5 to 1% solution 3.Use surfactant at 0.25% 4.Adhere to irrigation restrictions for imazapyr, may cause off-target damage

19. Useful Links Floridata Homepage: http://www.floridata.com/main_fr.cfm?state =Welcome&viewsrc=welcome.htm http://www.floridata.com/main_fr.cfm?state =Welcome&viewsrc=welcome.htm University of Florida Center for Aquatic and Invasive Plants: http://aquat1.ifas.ufl.edu/welcome.html http://aquat1.ifas.ufl.edu/welcome.html University of Florida’s Cooperative Extension Electronic Data Information Source: http://edis.ifas.ufl.edu/index.htmlhttp://edis.ifas.ufl.edu/index.html

20. Literature Cited Langeland, K.A. and K. Craddock Burks. 1998. Identification and Biology of Non- Native Plants in Florida's Natural Areas. IFAS Publication SP 257. University of Florida, Gainesville. 165 pp