Red cestrum (Cestrum elegans)

Also known as: elegant poison berry

Red cestrum is a hairy shrub with small red tubular flowers. All parts of the plants are poisonous to people and animals.

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How does this weed affect you?

Red cestrum forms dense thickets. It:

  • is poisonous to people, pets, livestock and native animals
  • can cause skin rashes
  • outcompetes native plants
  • reduces food and shelter for native animals
  • may reduce livestock productivity when infested pastures cannot be grazed due to poisoning
  • can restrict movement of people and animals.

Human poisoning

All parts of the plant are toxic, especially the berries.  Avoid touching the plant with bare skin and if the plant is accidentally touched wash the skin thoroughly.

What to do if a person is poisoned:

  • If the patient is unconscious, unresponsive or having difficulty breathing dial 000 or get to the emergency section of a hospital immediately.
  • If the patient is conscious and responsive call the Poisons Information Centre on 13 11 26 or your doctor.
  • If going to a hospital take a piece of the plant for identification.

Livestock poisoning

Red cestrum can cause death in livestock. Remove stock from paddocks when controlling red cestrum. Do not return stock until plants have disintegrated or been removed.

What does it look like?

Red cestrum is a perennial shrub up to 5 m tall. It can be either single or multi-stemmed at the base. Most parts of the plant are covered with fine purple hairs.

Leaves are:

  • dull green on top and paler green on the underside
  • oval to spear shape with pointed tips
  • 7–11.5 cm long, 2.5–5.5 cm wide
  • hairy all over when young and then just on the veins when older
  • on a stalk  up to 1.5 cm long
  • alternate along the stem.
  • smell foul when crushed (caution wear gloves when handling plants).

Flowers are:

  • pinkish red to pinkish purple 
  • tubular shaped with five triangular lobes at the end
  • up to 23 mm long and up to 5 mm wide
  • in tightly packed clusters 
  • mostly present from winter to spring.

Fruit are:

  • red or pink berries
  • rounded
  • 6–13 mm diameter.

Stems are:

  • branched
  • hairy with purple hairs when younger
  • woody when older.

Similar looking plants

Red cestrum looks similar to early flowering jessamine (Cestrum fasciculatum), which has larger flowers. There are also hybrids of red cestrum and early flowering jessamine.

Where is it found?

In NSW, red cestrum has been found in:

  • the South East region near Wollongong and the southern highlands
  • the North Coast region near Bellingen and Port Macquarie.
  • Newcastle in the Hunter region
  • several locations in Greater Sydney.

Red cestrum is native to southern Mexico.

What type of Environment does it grow in?

Red cestrum can grow in a wide range of climate and soil conditions and is tolerant to drought and shade. It has been found growing along rainforest edges, in wet sclerophyll forests, along waterways and in paddocks..

Maps and records

  • Recorded presence of Red cestrum during property inspections (Map: Biosecurity Information System - Weeds, 2017-2022)
    These records are made by authorised officers during property inspections under the Biosecurity Act 2015. Officers record the presence of priority weeds in their council area and provide this to the NSW Department of Primary Industries. Records reflect the presence of the weed on the date of inspection.

How does it spread?

Red cestrum has been planted in gardens as an ornamental plant.

By seeds

Red cestrum can start producing seeds when it is less than a year old. Each plant can produce up to 1500 seeds per year and the seeds can remain viable for up to 8 years. Birds eat the fruit and spread the seed in their droppings. If plants are on the edge of waterways the seeds spread downstream. Seeds could also be spread in contaminated soil or mud. 

By plant parts

Red cestrum can grow from stem and root fragments which can be spread by garden dumping. The plants sucker readily, which quickly increases the size of the infestations.

References

Colorado State University (2021). Guide to poisonous plants. Retreived 23 November 2021 from: https://csuvth.colostate.edu/poisonous_plants/Plants/Details/121.

Identic and Lucid (2016). Weeds of Australia: Cestrum elegans (Brongn. ex Neumann) Schltdl. Retreived 23 November 2021 from:https://keyserver.lucidcentral.org/weeds/data/media/Html/cestrum_elegans.htm#Naturalised%20Distribution

Muyt, A. (2001). Bush invaders of South-East Australia: a guide to the identification and control of environmental weeds found in South-East Australia. RG and FJ Richardson.

NZ Weedbusters (2021) Weed information sheet: Red cestrum. Retreived 23 November 2021 from: https://www.weedbusters.org.nz/what-are-weeds/weed-list/red-cestrum/

PlantNET (The NSW Plant Information Network System). Royal Botanic Gardens and Domain Trust, Sydney. Retrieved 22/11/2021 from https://plantnet.rbgsyd.nsw.gov.au/cgi-bin/NSWfl.pl?page=nswfl&lvl=sp&name=Cestrum~elegans

Stewart-Howie, M. (2003). Environmental weed treatment in Melbourne's water catchment. Plant Protection Quarterly18(2), 70-71.

VicFlora (2016). Flora of Victoria, Royal Botanic Gardens Victoria, Retrieved 23 November 2021 from: https://vicflora.rbg.vic.gov.au/flora/taxon/b390b014-45ca-49e7-a291-ef43948b2b2d

More information

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Control

Successful weed control relies on follow up after the initial efforts. This means looking for and killing regrowth or new seedlings. Using a combination of control methods is usually more successful.

Wear gloves and other personal protective clothing when controlling red cestrum to prevent coming into contact with the plant.

To manage red cestrum:

  • control young plants before they mature
  • treat mature plants before they flower
  • control regrowth from treated plants
  • keep checking for new seedlings for many years because seeds can remain dormant in the soil.  

Hand removal

Seedlings can be pulled or dug out when small. Larger plants are difficult to remove due to their extensive roots and because it is difficult to limit contact with the larger plants. Dispose of plants carefully as stems can reshoot if left touching the soil. 

Disposal

Contact your local council for advice on how to dispose of this poisonous plant.

Chemical control

Spraying

Spray actively growing plants and ensure that all the foliage is covered with the herbicide. Keep stock away from dead plant material as it remains poisonous. 

Cut and paint

Cut the stem and apply herbicide within 15 seconds of cutting.  Dispose of the cut part of the plant carefully as stems can reshoot if left touching the soil. 

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

See Using herbicides for more information.


PERMIT 9907 Expires 31/03/2025
Glyphosate 360 g/L (Various products)
Rate: Up to 1:50 herbicide to water.
Comments: Spot spray. See permit for additional conditions.
Withholding period: Nil.
Herbicide group: M, Inhibitors of EPSP synthase
Resistance risk: Moderate


PERMIT 9907 Expires 31/03/2025
Glyphosate 360 g/L (Various products)
Rate: 1:1.5 with water to undiluted herbicide.
Comments: Cut, scrape and paint. See permit for additional conditions.
Withholding period: Nil.
Herbicide group: M, Inhibitors of EPSP synthase
Resistance risk: Moderate


Picloram 44.7 g/L + Aminopyralid 4.47 g/L (Vigilant II ®)
Rate: Undiluted
Comments: Cut stump application. Apply a 3–5 mm layer of gel for stems less than 20 mm. Apply 5 mm layer on stems above 20 mm .
Withholding period: Nil.
Herbicide group: I, Disruptors of plant cell growth (synthetic auxins)
Resistance risk: Moderate


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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.
North Coast Regional Recommended Measure* (for Regional Priority - Eradication)
Land managers should mitigate the risk of new weeds being introduced to their land. The plant should be eradicated from the land and the land kept free of the plant. The plant should not be bought, sold, grown, carried or released into the environment. Notify local control authority if found.
*To see the Regional Strategic Weeds Management Plans containing demonstrated outcomes that fulfil the general biosecurity duty for this weed click here

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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

Reviewed 2022