Calomba Daisy

Oncosiphon suffruticusom

Calomba Daisy

Calomba Daisy is an annual weed of perennial pastures and coastal vegetation occuring mainly in the lower rainfall areas north of Adelaide.

It is a declared weed under the Natural Resources Management Act 2004 (NRM Act).

Description

  • an erect annual herb that grows to about 60 cm high
  • stems are stout and woody
  • leaves are grey-green and finely divided with a feather-like appearance and a strong chamomile odour
  • first leaves form a small rosette from which an erect, leafy flowering stem grows
  • flowers are minute, mustard yellow and arranged at the ends of the stems in broad, flat ball-shaped heads
  • flowers appear in August and September
  • plants die in early summer leaving the dry woody stems which carry the seeds
  • some seeds disperse by wind but most remain in the flower head until it breaks up
  • seeds germinate in response to summer rain, and multiple germination events can occur in a single year.

Impacts

  • unpalatable to stock and displaces desirable pasture plants
  • If eaten by stock, Calomba Daisy can taint meat and milk products
  • dense stands can reduce the yield of cereal crops. However it is rarely a problem in crops as it is effectively controlled by pre-emergent and broad-leaf herbicides.

Distribution

  • originates from South Africa. It is thought to have been introduced to South Australia in contaminated fodder in 1922
  • occurs mainly in perennial pastures in the lower rainfall areas north of Adelaide
  • marginal cropping areas are most vulnerable, particularly fallow paddocks
  • occurs in native coastal plant communities on raised sandy soils
  • mainly invades degraded areas but can displace established samphire vegetation.

How to control this weed

  • in semi-arid pastures Calomba Daisy can be controlled by maintaining pasture by light grazing
  • small infestations can be managed by hoeing or spot spraying
  • for advice on chemical control techniques contact your nearest Natural Resources Centre
  • refer to the 'Weed control handbook for declared plants in South Australia' for advice on chemical control. You can find it on the Biosecurity SA website.

Declarations

The following sections of the NRM Act apply to Calomba Daisy in the Adelaide and Mount Lofty Ranges region:

  • 175 (2) Cannot transport the plant, or any material or equipment containing that plant, on a public road
  • 177 (1) Cannot sell the plant
  • 177 (2) Cannot sell any produce / goods carrying the plant
  • 182 (2) Landowner must control the plant on their land
  • 185 (1) NRM authority may recover costs for control of weeds on roadsides from adjoining landowners

More information

For more detailed information download the fact sheet.

Please contact us for advice and assistance with controlling Calomba Daisy.

Natural Resources Adelaide and Mount Lofty Ranges