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Arctotheca calendula (L.) K.Lewin
Cape Weed

Repert.Spec.Nov.Regni Veg.Beih. 11:49 (1922)
Conservation Code
Not threatened
Naturalised Status
Alien to Western Australia
Name Status

Decumbent or ascending annual, herb, 0.03-0.3 m high. Fl. yellow, Aug to Nov. Weed of roadsides, waste places & cultivated land.

Amanda Spooner, Descriptive Catalogue, 18 April 1997


IBRA Regions
Avon Wheatbelt, Carnarvon, Coolgardie, Esperance Plains, Geraldton Sandplains, Hampton, Jarrah Forest, Mallee, Murchison, Pilbara, Swan Coastal Plain, Warren, Yalgoo.
IBRA Subregions
Cape Range, Eastern Goldfield, Eastern Mallee, Eastern Murchison, Edel, Fitzgerald, Geraldton Hills, Hampton, Katanning, Lesueur Sandplain, Merredin, Northern Jarrah Forest, Perth, Recherche, Roebourne, Southern Cross, Southern Jarrah Forest, Tallering, Warren, Western Mallee, Western Murchison.
IMCRA Regions
Central West Coast, Leeuwin-Naturaliste, WA South Coast.
Local Government Areas (LGAs)
Albany, Armadale, Ashburton, Augusta Margaret River, Beverley, Boyup Brook, Bridgetown-Greenbushes, Busselton, Capel, Carnamah, Chapman Valley, Chittering, Cockburn, Collie, Coolgardie, Coorow, Cuballing, Cunderdin, Dalwallinu, Dandaragan, Donnybrook-Balingup, Dowerin, Dumbleyung, Dundas, Esperance, Exmouth, Gingin, Goomalling, Gosnells, Greater Geraldton, Harvey, Jerramungup, Joondalup, Kalgoorlie-Boulder, Karratha, Kellerberrin, Kent, Kondinin, Koorda, Lake Grace, Laverton, Mandurah, Manjimup, Melville, Merredin, Mingenew, Moora, Morawa, Mount Marshall, Mukinbudin, Mundaring, Murray, Narembeen, Narrogin, Nedlands, Northam, Northampton, Perenjori, Perth, Pingelly, Plantagenet, Ravensthorpe, Rockingham, Serpentine-Jarrahdale, Shark Bay, South Perth, Swan, Tammin, Toodyay, Trayning, Victoria Plains, Wagin, Wandering, Wanneroo, Waroona, West Arthur, Wickepin, Williams, Wongan-Ballidu, Wyalkatchem, Yalgoo, Yilgarn, York.

Management Notes (for the Swan NRM Region)

Alternative Names. Cape Dandelion, Plain Treasure-flower, Fertile Capeweed.

General Biology. Growth form. Herb. Life form. Annual. Reproduction. Seed, stolons. Dispersal. Wind, water, movement of contaminated soil or mud, animals. Toxicity. Can be poisonous to mammals, through accumulating potentially toxic levels of nitrate. Seedbank persistence. Highly variable, but may be up to 8 years.

Notes. Widespread and common in temperate areas. Can be biennial. Colonises bare soil and disturbed sites. It is likely to impact on soil moisture and nutrient availability, however does not seems to compete well in natural undisturbed ecosystems. Seems to be a relatively poor competitor with native species, but if established can have a moderate impact on native plant communities. Can reproduce vegetatively by stolon fragments. Germination is promoted by light. The early onset of low winter temperatures may postpone germination until the following autumn. Biotypes have evolved resistance to Group D/22 (Bipyridiliums) and Group L herbicides. Can go on to produce seed under defoliation. Persistence of seed in the soil is strongly influenced by the ecotype/location and degree of burial. Low rainfall events can favour capeweed germination before other species as the woolly seed cover attracts moisture and reduces desiccation. Seed dormancy is overcome by high summer temperatures. There may be large differences in seed dormancy characteristics, with genetically distinct populations adapted to particular environments..

Additional information. Origin. Southern Africa. History of use/introduction. Seed contaminant.

Suggested method of management and control. Chip out small infestations,ensuring root is severed well below ground level to prevent re-sprouting from the crown. For large infestations apply Lontrel® 6 ml/10 L (300 ml/ha) in early growth stages. Glyphosate at 0.2% will provide some selective control if the plants are young or at the budding stage, otherwise spot spraying glyphosate at 10 ml/L will control capeweed at all growth stages. A combination of chemical and physical control with follow up treatment provides optimal control. 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

Calendar Type Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Comments
Active Growth           Y Y Y Y Y Y    
Germination     O Y Y O O O O       Germinates after rains
Flowering               Y Y Y Y    
Fruiting                   Y Y Y  
Optimum Treatment           Y Y Y Y Y Y    

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



  • Brown, K. & Brooks, K. (2002) Bushland Weeds: A Practical Guide to their Management. Environmental Weeds Action Network, Greenwood.
  • Chaharsoghia, A.T. & Jacobs, B. (1998) Manipulating dormancy of capeweed (Arctotheca calendula L.) seed. Seed Science Research, 8: 139-146.
  • Dixon, B. (2006) Control of Arctotheca calendula amongst the critically endangered Corrigan grevillea Grevillea scapigera on translocation sites in the wheatbelt of Western Australia. In Managing Weeds in a Changing Climate: Australian weeds conference, 15th, 24-28 Sep 2006, Adelaide SA, eds Preston, C., Watts, J.H., Crossman, N.D. p288-290.
  • Dunbaben, M.T. & Cocks, P.S. (1999) Ecotypic variation for seed dormancy contributes to the success of capeweed (Arctotheca calendula) in Western Australia. Australian Journal of Agricultural Research, 50: 1451-8.
  • Ellery, A.J. (2002) Embryo dormancy responses to temperature in capeweed (Arctotheca calendula) seeds. Seed Science Research, 12: 181-191.
  • Ellery, A.J. & Chapman, R. (2000) Embryo and seed coat factors produce seed dormancy in capeweed (Arctotheca calendula). Australian Journal of Agricultural Research, 51: 849-854.
  • Finley, E. (2003) Part IV: Plant Assessment Form: Arctotheca calendula (L) Levyns (fertile varieties). California Invasive Plant Council URL: - Accessed April 2010.
  • Grist, A. & Thompson, P. (1997) Weed control in direct seeding areas-selective herbicides. Western Wildlife, 1 (3) Newsletter for the Land for Wildlife Scheme.
  • Hester, A.J. & Hobbs, R.J. (1992) Influence of fire and soil nutrients on native and non-native annuals at remnant vegetation edges in the Western Australian wheatbelt. Journal of Vegetation Science, 13 (1): 101-108.
  • 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.
  • McIvor, J.G. & Smith, D.F. (1973) Competitive growth of capeweed, Arctotheca calendula, and some annual pasture species. Australian Journal of Experimental Agriculture and Animal Husbandry, 13 (61): 185-189.
  • McIvor, J.G. & Smith, D.F. (1973b) The effect of defoliation on seed production by capeweed (Arctotheca calendula). Australian Journal of Experimental Agriculture and Animal Husbandry, 13 (65): 676 - 680.
  • Moore, C.B. & Moore, J.H. (2002) Herbiguide, the pesticide expert on a disk. Herbiguide, PO Box 44 Albany, Western Australia, 6330.
  • Stevens, J.C., Merrit, D.J., Flematti, G.R., Ghisalberti, E.L. & Dixon, K.W. (2007) Seed germination of agricultural weeds is promoted by the butenolide 3-methyl-2H-furo(2,3-cpyran-2-one) under laboratory and field conditions. Plant Soil, 298: 113-124.
  • USDA, ARS, National Genetic Resources Program (2009) Germplasm Resources Information Network - (GRIN). National Germplasm Resources Laboratory, Beltsville, Maryland. URL: - Accessed October 2009.
  • Wood, H. (1994) The introduction and spread of capeweed, Arctotheca calendula (L.) Levyns (Asteraceae) in Australia. Plant Protection Quarterly, 9 (3): 94-100.