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Boneseed flower © DBCA

Boneseed

Chrysanthemoides monilifera subsp. monilifera

Quick facts

Status
Declared Pest - Prohibited s12, WoNS
Life Cycle
Perennial
Growth Form
Shrub / Small Tree
Origin
South Africa
Flowers
Yellow
Dispersal
Birds,other animals

Names

Synonyms: ​​Osteospermum moniliferum subsp. moniliferum​ 

Form and function

Upright shrub of medium leaf density growing to 3m and flowers in spring.  Fruit produced after the second year of growth.  Forms a highly persistent seedbank, with seeds remaining viable in the soil for up to 15 years. Mature plants are generally killed by high-intensity fire, and may survive lower-intensity fires. Fire can also stimulate the germination of dormant seeds, although seeds located in the upper soil layers usually don’t survive.  Highly attracted to birds that can facilitate dispersal.

Flowers

  • Yellow daisy-like flowers.
  • 4-8 petals per flower.
  • Up to 3 cm in diameter.
  • Grows in clusters at the end of branches.

Boneseed flower © DBCA

Leaves

  • Oval shaped with irregular toothed edges.
  • Sometimes lobed with pointed tips on the lobes.
  • Usually up to 6 cm long and up to 3 cm wide (occasionally up to 9 cm long).
  • Covered in a fluffy white hairs that resemble cobwebs when rubbed.
  • Becomes hairless when mature.
  • Alternate along the stems.

Boneseed flower © DBCA

Fruits

  • Round, fleshy berries ripening from green to black.
  • 6–8 mm in diameter.
  • Each fruit contains a single hard-coated seed, white to grey once the flesh has broken down.

Boneseed fruits © DBCA

Roots

  • Shallow root system.

Boneseed mature tree roots © DBCA

Habitat

Typically found on clay-gravel soils, along roadsides and in bushland. In Western Australia its found in several wheatbelt towns and in the most problematic infestations are in the Perth Hills areas around Kalamunda and Roleystone.  Bird dispersal allows it to distribute to new areas and seedlings generally found at the base of trees.

May be confused with...

Similar native species: Yellow Buttercups (Hibbertia hypericoides).

Hibbertia hypericoides flowering plant © t_carnifex
Hibbertia hypericoides © t_carniflex

Similar non-native species: ​​Flax-leaf Broom (Genista linifolia) and Montpellier Broom (Genista monspessulana). May also be confused with Bitou Bush (Chrysanthemoides monilifera subsp. rotundata), however the distribution of the two subspecies does not overlap.

Montpellier broom flowers. DBCA
Montpellier Broom (Genista monspessulana) © DBCA

How does it spread?

​​Seed dispersal by birds, foxes, water, soil, machinery and in garden refuse​. 

Why is it a weed?

Aggressively invades native bushland and easily establishes across a wide range of vegetation communities. Its rapid growth, lack of natural enemies and ability to regenerate quickly after fire allow it to outcompete native plants and spread extensively. As a result, it can alter natural ecosystems and threaten rare and threatened native species. Its shallow root system allows it to out compete surrounding plants as it absorbs moisture from light summer rainfall which doesn’t penetrate deep enough for neighbouring, native deep-rooted species.

How to control

Due to the extensive quantity and duration of Boneseed’s seedbank, long term control is necessary, and consistent follow-ups must be carried out for several years for successful treatment.

Physical

Seedlings and juvenile plants can be hand pulled as they have shallow roots with no tap root. Larger plants can also be hand pulled if the soil is damp, gravelly or sandy.  Best method here is to grab the trunk and rock the shrub back and forth until the roots loosen, then the plant can but pulled out and upturned. Hand tools may be required in drier and heavier soils.  Broken root fragments left in the soil won’t give rise to new plants.

Hand removal of tree © DBCA

Chemical

​​Due to bonseed having a high seed bank, a single herbicide application will not be sufficient as seedlings will rapidly replace treated plants. A follow-up treatment post new seedling germination will likely be required, otherwise conduct the first herbicide treatment just prior to flowering period. Performing a later initial herbicide application on larger Boneseed plants is likely to require a higher rate but decrease the need for secondary treatment.

  • Cut stump: Glyphosate 360 g/L at 50%.  Cut trunk with handsaw and paint with herbicide immediately. Herbicide can be added at intervals during cutting. 
  • ​Foliar spray: Glyphosate 360 g/L at 5 or 10 mL/ 1 L water, ensuring full leaf coverage. Best results achieved when treated at peak flowering during winter. Use higher rate on plants over 1.5 m high.
  • Tebuthiuron 200 g/kg at 1.5–2g per m2. Sprinkle evenly over the ground after removing mature plants. This is a soil residual herbicide that will target germinating seed in the seed bank if follow up control cannot occur in the next year.  Do not apply near water catchments or areas with high surface run off.  Note tebuthiuron is non-selective and will affect all plants and seedlings attempting to grow while active int the soil.
Cut trunk with handsaw and paint with herbicide immediately © DBCA

Managerial

Controlled burns should be considered for larger infestations and only if a program of followup control can be applied to address the stimulated seedbank.  All burn events will need to consider a program of follow up control as the burns will stimulate the seedbank to germinate.

Weed Distribution Map

LSID number: [2913231] | full LSID: [https://id.biodiversity.org.au/node/apni/2913231] | field_lsid: [] | taxon: ["Chrysanthemoides monilifera"]

ALA Reference

References

  • A. Ghafoor Chrysanthemoides monilifera subsp. rotundata, in (ed.), Flora of Australia. Australian Biological Resources Study, Department of Climate Change, Energy, the Environment and Water: Canberra.
  • Batchelor, K., Scott. J.K., Webber. B.L. (2022) Boneseed and bitou bush in Western Australia: a tale of two Chrysanthemoides. Council of Australasian Weed Societies (CAWS).
  • CRC for Australian Weed Management. (2000) Best Practice Management Guide Boneseed, Chrysanthemoides monilifera subsp. monilifera. ISSN 1442-7192
  • Cherry H. (2010) Western Australia Boneseed Eradication Strategy. Unpublished Report. Government of Western Australia (2007) 'Biosecurity and Agriculture Management Act 2007.'
  • CRC for Australian Weed Management (2003) Boneseed (Chrysanthemoides monilifera ssp. monilifera) Weed management guide. ISBN 1-920932-01-1.
  • Department of Biodiversity, Conservation and Attractions. (2026) Fire Facts Government of Western Australia
  • Department of Primary Industries and Regional Development. (2026 Western Australian Organism List (WAOL)
  • VicFlora (2026) Flora of Victoria, Royal Botanic Gardens Victoria.
  • Western Australian Herbarium (1998–) Florabase—the Western Australian flora. Department of Biodiversity, Conservation and Attractions.
  • NSW WeedWise Boneseed (Chrysanthemoides monilifera subsp. monilifera)

Life Cycle

JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC Notes
Germination
Flowering
Fruiting
Regularly or most commonly
Occasionally, given suitable conditions

Management

JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC Notes
Hand removal
Foliar spray
Cut stump
Optimal
Potentially, but conditionally dependent
Last updated: October 2026