Euphorbia terracina L.
Geraldton Carnation Weed

Management Notes (for the Swan NRM Region)

Alternative Names. False Caper, Geraldton Carnation Spurge, Terracina Spurge.

General Biology. Growth form. Herb. Life form. Short-lived perennial. Reproduction. Seed. Dispersal. Local spread by fruit opening explosively, birds, ants, movement of limestone soils and by machinery. . Sap is poisonous and an irritant. Seedbank persistence. 3-5 years. Fire response. Plants are generally killed by fire, however some resprout. Fire may cause mass germination of soil-stored seed.

Notes. Most common on coastal sandy nutrient-poor calcareous soils, also capable of spreading into fertile inland soils, ephemeral wetlands and saline depressions. Invasion into natural areas is greatly enhanced by disturbance such as grazing, fire and soil movement. Once established is able to invade relatively undisturbed vegetation. Has alleolopathic properties, can reduce germination of other plant species, form dense thickets and out compete native species for space, light and nutrients. Has rapid growth and prolific seed production in the first season. Can grow well or adapt to shade and high light conditions, tolerant of waterlogging and drought. Toxic sap deters native herbivores. Loses most of its leaves during summer. Germination may occurr at any time of the year if there is adequate rainfall. If there is insufficient rainfall, depletion of the seed bank may be relatively slow. Plants from early cohorts produce greater numbers of seeds per plant than late cohorts. Disturbance that brings seed to the soil surface should be avoided, as buried seed is far less likely to germinate. Mature plants have a deep root system and are able to resprout readily when cut, grazed or burnt. Similarly, seedlings are not easily killed through slashing or any physical means that do not remove the enitre plant. Resprouting plants are often more robust and have greater seed output.

Additional information. Origin. Mediterranean coast and islands, Canary Islands in the Atlantic, north of the Red Sea and the Black Sea to Georgia. History of use/introduction. The reasons for its introduction are uncertain, however many species of Euphorbia are used as ornamentals. Similar exotic species. E. peplus, E. paralias.

Suggested method of management and control. Logran® at 12.5 g/100L + the penetrant Pulse ® is very effective on adults and juveniles with little offtarget damage in coastal heathlands. Hand removal can stimulate germination of the soil seedbank. Ensure adequate personal protective clothing is worn to avoid contact with sap. Since seed production is highest from plants which emerge early, it is important to control early cohorts, if not treated when small these become increasingly tolerant to herbicides. Control of the late emergents before seed formation will prevent fresh seeds being added to the existing seed bank. Slashing in November after seed production may result in no vegetative regeneration, due to lack of food reserves in the underground roots and stem - the remaining underground plant parts cannot withstand hot dry summer conditions. Undertake control after any fire event. Read the manufacturers' labels and material safety data sheets before using herbicides. For further information consult the Australian Pesticides and Veterinary Medicines Authority to determine the status of permits for your situation or state.

Management Calendar

Legend: Y = Yes, regularly, O = Occasionally, U = Uncertain, referred by others but not confirmed.

References

• Brigham, C. (2006) Euphorbia terracina: be afraid, be very afraid. URL: http://www.cal-ipc.org/symposia/archive/pdf/2006/EDBrigham.pdf - Accessed March 2010.
• Brown, K. & Brooks, K. (2002) Bushland Weeds: A Practical Guide to their Management. Environmental Weeds Action Network, Greenwood.
• Brown, K. & Cullity J. (2007) Geraldton Carnation Weed; Managing invasion into a threatened ecological community, the Holocene dune swales at Point Becher. In Geraldton Carnation Weed (Euphorbia terracina) Workshop and Field Day. Proceedings of a conference held at Naragebup Rockingham Regional Environment Centre (ed Urban Nature). Department of Environment and Conservation, Perth. URL: http://www.dec.wa.gov.au/programs/urban-nature/publications.html - Accessed June 2009.
• Brown, K., Cullity, J. & Paczkowska, G. (2014) Recovery of Native Plant Communities following Control of Terracina Spurge (Euphorbia terracina): Three Case Studies from South-west Western Australia. Ecological Restoration, 32 (1): 37-45.
• Cheam, A.H. & Lee, S.I. (1996) Ecology of Geraldton Carnation Weed. Department of Agriculture and Food Western Australia, South Perth.
• Department of Primary Industries (2009) Invasiveness Assessment - False Capers (Euphorbia terracina) in Victoria. State of Victoria URL: http://www.dpi.vic.gov.au/DPI/VRO/vrosite.nsf/pages/invasive_false_capers - Accessed February 2010.
• Dixon, B. (1998) Control of weeds in bushland. In What's in the Toolbox; Proceedings of the Way with Weeds Conference. Held at Muresk Agricultural College, Northam, Western Australia, March 9 and 10, 1998.
• Hussey, B.M.J., Keighery, G.J., Dodd, J., Lloyd, S.G. & Cousens, R.D. (2007) Western Weeds. A guide to the weeds of Western Australia. 2nd Edition. The Plant Protection Society of Western Australia, Victoria Park.
• Keighery, G.J. & Keighery. B.J. (2007) Biology and weed risk in Western Australia. In Geraldton Carnation Weed (Euphorbia terracina) Workshop and Field Day. Proceedings of a conference held at Naragebup Rockingham Regional Environment Centre (ed Urban Nature). Department of Environment and Conservation, Perth. URL: http://www.dec.wa.gov.au/programs/urban-nature/publications.html - Accessed June 2009.
• Parsons, W.T. & Cuthbertson, E.G. (2001) Noxious weeds of Australia. 2nd Edition. CSIRO Publishing, Collingwood.
• Pemberton, R.W. & Irving, D.W. (2008) Elaiosomes on weed seeds and the potential for myrmecochory in naturalized plants. Weed Science, 38 (6): 615-619.
• Riordan, E.C., Rundel, P.W., Brigham, C. & Tiszler, J. (2008) Morphological traits and invasive potential of the alien Euphorbia terracina (Euphorbiaceae) in coastal southern California. Madroño, 55 (1): 52-59.
• Urban Nature (ed.) (2007) Geraldton Carnation Weed (Euphorbia terracina) Workshop and Field Day. Proceedings of a conference held at Naragebup Rockingham Regional Environment Centre. URL: http://www.dec.wa.gov.au/programs/urban-nature/publications.html - Accessed June 2009.
• USDA, ARS, National Genetic Resources Program (2009) Germplasm Resources Information Network - (GRIN). National Germplasm Resources Laboratory, Beltsville, Maryland. URL: https://npgsweb.ars-grin.gov/gringlobal/taxon/taxonomysimple.aspx - Accessed October 2009.
• Ventura County Resource Conservation District (Undated) Plant Information Sheet: Euphorbia terracina. URL: http://www.vcwma.org/pdfs/EUPHORBIA%20TERRACINA.pdf - Accessed February 2010.