Koster's curse (Clidemia hirta)
PROHIBITED MATTER: If you see this plant report it. Call the NSW DPI Biosecurity Helpline 1800 680 244
Also known as:
clidemia, soapbush, hairy clidemia
Koster’s curse is a highly invasive perennial shrub that rapidly forms dense thickets, invading forests, plantations and pastures and smothering native vegetation.
Profile
How does this weed affect you?
Koster’s curse is a highly invasive perennial shrub that rapidly forms dense thickets, invading forests, plantations and pastures and smothering native vegetation. It is capable of growing in undisturbed areas, giving it the potential to cause widespread damage to sensitive native vegetation. In disturbed areas it will increase rapidly once introduced.
Where is it found?
Koster’s curse originates from South America, from Mexico, through to northern Argentina and the Caribbean Islands. In its native range Koster’s curse is not found in forests, yet it is a highly invasive weed in tropical forests where it has been introduced.
Koster’s curse is considered a serious weed in Hawaii, tropical Pacific islands (Fiji, Samoa and Vanuatu), Southeast Asia (Thailand to New Guinea) and the Indian Ocean islands (Seychelles, La Reunion, Mauritius and Madagascar). It has become naturalised on the Indian subcontinent (India, Bangladesh, Bhutan, Nepal, Sri Lanka and Pakistan) and in Tanzania.
In Australia, an infestation was first detected in 2001 near Julatten in far north Queensland. It is thought to have entered the country from contaminated packaging material. This infestation is currently subject to a national eradication campaign.
Koster’s curse has not been detected in New South Wales (NSW), but has the potential to invade the humid northern coastal areas.
How does it spread?
In ideal conditions, each plant is capable of producing thousands of seeds per year. Dispersal of seed is mostly by berry eating birds, but can also be spread by contaminated soil movement.
Seeds can remain viable in the soil for at least four years. Seedling establishment is very successful and plants can reach full maturity in less than twelve months.
What does it look like?
Koster’s curse is a bushy perennial shrub covered in reddish-brown bristly hairs. It will generally grow to around 2 m high, although it can grow up to 5 m in moist, shady conditions.
Key identification features
- Leaves are hairy and occur in opposite pairs along the stem. They are widest around the middle, 5–14 cm long and 4–7 cm wide with toothed margins. The upper surfaces are a bright, shiny green, and the undersides are paler. Five prominent veins run down the length of the leaf, with many obvious cross veins occurring between.
- Clusters of 6–20 small flowers occur in the leaf forks or at the end of branches. They are 1–1.5 cm in diameter with 5 white or pinkish petals. Flowers occur all year, except in dry conditions.
- Each flower produces a reddish purple berry 4–5 mm in diameter which contains over a hundred very small seeds—about 0.6 mm in size. Berries are hairy and turn dark purple when mature.
What type of environment does it grow in?
Koster's curse prefers tropical climates with an annual rainfall over 1200 mm, growing in both shaded areas and full sunlight.
Acknowledgements
Reviewed by: Rod Ensbey Edited by: Elissa van Oosterhout, Birgitte Verbeek
References
Queensland Government—Department of Employment, Economic Development and Innovation (2011) Fact sheet—Koster’s curse Clidemia hirta
Hosking JR, Sainty GR, Jacobs SWL & Dellow LL (in prep) The Australian WeedBOOK.
Control
IYou must report this plant if you see it anywhere in NSW. Call the helpline listed above. Help will then be provided to remove and destroy it. This serious weed could spread if control efforts do not follow all protocols. Not reporting it is a breach of your legal biosecurity duty.
Herbicide options
WARNING - ALWAYS READ THE LABEL
Users of agricultural or veterinary chemical products must always read the label and any permit, before using the product, and strictly comply with the directions on the label and the conditions of any permit. Users are not absolved from compliance with the directions on the label or the conditions of the permit by reason of any statement made or not made in this information. To view permits or product labels go to the Australian Pesticides and Veterinary Medicines Authority website www.apvma.gov.au
Users of agricultural or veterinary chemical products must always read the label and any permit, before using the product, and strictly comply with the directions on the label and the conditions of any permit. Users are not absolved from compliance with the directions on the label or the conditions of the permit by reason of any statement made or not made in this information. To view permits or product labels go to the Australian Pesticides and Veterinary Medicines Authority website www.apvma.gov.au
See Using herbicides for more information.
PERMIT 9907 Expires 31/03/2020
Fluroxypyr 200 g/L
(Starane™)
Rate: 500 mL to 1 L per 100 L water
Comments: Spot spray
Withholding period: 7 days.
Herbicide group: I, Disruptors of plant cell growth (synthetic auxins)
Resistance risk: Moderate
PERMIT 9907 Expires 31/03/2020
Fluroxypyr 333 g/L
(Starane™ Advanced)
Rate: 300 to 600 mL per 100 L water
Comments: Spot spray
Withholding period: 7 days.
Herbicide group: I, Disruptors of plant cell growth (synthetic auxins)
Resistance risk: Moderate
PERMIT 9907 Expires 31/03/2020
Glyphosate 360 g/L
(Roundup®)
Rate: One part product to 50 parts water
Comments: Spot spray
Withholding period: Nil.
Herbicide group: M, Inhibitors of EPSP synthase
Resistance risk: Moderate
PERMIT 9907 Expires 31/03/2020
Glyphosate 360 g/L
(Roundup®)
Rate: One part product to 9 parts water
Comments: Splatter gun
Withholding period: Nil.
Herbicide group: M, Inhibitors of EPSP synthase
Resistance risk: Moderate
PERMIT 9907 Expires 31/03/2020
Glyphosate 360 g/L
(Roundup®)
Rate: One part product to 20 parts water
Comments: Wipe onto leaves
Withholding period: Nil.
Herbicide group: M, Inhibitors of EPSP synthase
Resistance risk: Moderate
PERMIT 9907 Expires 31/03/2020
Metsulfuron-methyl 600 g/kg
(Brush-off®)
Rate: 10 - 20 g per 100 L water plus surfactant
Comments: Spot spray
Withholding period: Nil (recommended not to graze for 7 days before treatment and for 7 days after treatment to allow adequate chemical uptake in target weeds).
Herbicide group: B, Inhibitors of acetolactate synthase (ALS inhibitors)
Resistance risk: High
PERMIT 9907 Expires 31/03/2020
Metsulfuron-methyl 600 g/kg
(Brush-off®)
Rate: 10 g per 1 L of water plus surfactant
Comments: Wipe onto leaves
Withholding period: Nil (recommended not to graze for 7 days before treatment and for 7 days after treatment to allow adequate chemical uptake in target weeds).
Herbicide group: B, Inhibitors of acetolactate synthase (ALS inhibitors)
Resistance risk: High
Biosecurity duty
The content provided here is for information purposes only and is taken from the Biosecurity Act 2015 and its subordinate legislation, and the Regional Strategic Weed Management Plans (published by each Local Land Services region in NSW). It describes the state and regional priorities for weeds in New South Wales, Australia.
| Area | Duty |
|---|---|
| All of NSW | General Biosecurity Duty All plants are regulated with a general biosecurity duty to prevent, eliminate or minimise any biosecurity risk they may pose. Any person who deals with any plant, who knows (or ought to know) of any biosecurity risk, has a duty to ensure the risk is prevented, eliminated or minimised, so far as is reasonably practicable. |
| All of NSW |
Prohibited Matter
A person who deals with prohibited matter or a carrier of prohibited matter is guilty of an offence. A person who becomes aware of or suspects the presence of prohibited matter must immediately notify the Department of Primary Industries |
For technical advice and assistance with identification please contact your local council weeds officer.
For further information call the NSW DPI Biosecurity Helpline on 1800 680 244 or send an email to weeds@dpi.nsw.gov.au
For further information call the NSW DPI Biosecurity Helpline on 1800 680 244 or send an email to weeds@dpi.nsw.gov.au
Reviewed 2018
