Arum lily (Zantedeschia aethiopica)

Arum lily is an ornamental plant with large white flowers. All parts of the plant are poisonous to people and animals.

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How does this weed affect you?

Arum lily can:

  • make humans and animals very sick or die
  • choke waterways
  • reduce pasture productivity
  • stop other plants from growing.

Wetlands, waterways, irrigation ditches, forests, coastal areas and pastures are most affected. 

Human poisoning

Arum lily contains a mineral called calcium oxalate. All parts of the plant, especially the flower, are poisonous and can cause:

  • eczema and dermatitis 
  • irritation, burning and swelling of the mouth and throat
  • breathing difficulties
  • severe nausea, vomiting and stomach pain
  • diarrhoea
  • shock and exhaustion
  • death. 

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

It is not common for livestock to eat arum lily plants, but death can occur if they do. When ruminants (sheep, cattle and horses) eat arum lily it can cause:

  • irritation, burning and swelling of the mouth and throat
  • excessive drooling
  • vomiting
  • difficulty swallowing.

Poisoning of other animals

Arum lily can also be toxic to dogs, cats and birds. If you think you have affected animals contact your vet.

What does it look like?

Arum lily is a long-lived plant that is 1-1.5 m tall. It is known for its large, white flowers and recognisable leaves. New leaves grow from underground stems in autumn, followed by flowers in winter. Plants yellow off in areas with dry summers. In wet areas the plant is green year-round. 

Other varieties of arum lily are also invasive, including a green flowered version called ‘Green Goddess’.

Leaves are:
  • dark green and glossy
  • large (13-50 cm long, 8-25 cm wide)
  • leathery, often with wavy edges
  • arrow-shaped at the tip
  • heart-shaped at the base
  • attached to thick, fleshy stalks (40-150 cm long).
Flowers are:
  • large (10-26 cm long and 8-15 cm wide)
  • funnel-shaped, with a backwards pointing tip
  • white, with a central yellow or orange spike
  • present from winter to early summer.
Seeds are:
  • yellowy-brown
  • 3 mm wide
  • small and round
  • short lived
  • numerous, with single plants producing thousands per year.
Fruit are:
  • green-yellowish berries
  • orange and soft when ripe (summer)
  • oval-shaped
  • 0.5-1 cm wide
  • clustered in groups of 40-50
  • often hidden in the flower base.
Seeds are:
  • yellowy-brown
  • 3 mm wide
  • small and round
  • short lived
  • numerous, with single plants producing thousands per year.
Stems are:
  • Up to 1.5 m tall
  • smooth and fleshy 
  • attached to flowers.
Roots are:
  • fleshy, horizontal stems called rhizomes
  • large, underground systems
  • able to form new plants.

Similar looking plants

Arum lily can be confused with other plants, including

  • native cunjevoi (Alocasia brisbanensis). This plant has:
    • narrow, green flowers
    • spade-shaped leaves.
  • taro (Colocasia esculenta). This plant has:
    • green-yellow flowers 
    • green berries (rare).
  • Italian arum (Arum italicum). This plant has:
    • green flowers 
    • red berries
    • white and green spotted leaves.

Where is it found?

Arum lily is an environmental weed throughout Western Australia, South Australia, Tasmania, New South Wales and south-east Queensland. Arum lily is common in coastal areas of New South Wales. It is most invasive on Lord Howe and Norfolk Islands.

Arum lily is also a weed in New Zealand.

Arum lily comes from South Africa. It was brought to Australia as a garden plant.

What type of environment does it grow in?

Arum lily prefers wet, sunny areas but can also grow in full shade. It is hardy and can tolerate waterlogging, fire, occasional frost and salt. It can grow in tropical and cold areas.

Plants can grow in:

  • waterways and creek banks
  • wetlands and swamps
  • moist pastures
  • coastal areas
  • gardens
  • rubbish dumps
  • disturbed areas
  • roadsides
  • bush land.

Arum lily does not grow well in dry conditions or drought.

How does it spread?

Spread can be from plant parts or seed. It is also spread by people and is easy to buy in nurseries, plant markets and online.

By seed

Seeds can be spread by:

  • water
  • dumping of green waste
  • contaminated soil
  • birds
  • foxes
  • livestock.

Seeds germinate in late autumn to winter. 

By plant parts

A new plant can grow from a root, or root fragment. This happens locally when plants spread through root expansion, but roots can also be spread in:

  • water
  • dumping of green waste
  • contaminated soil.

 

More information

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Control

Successful weed control requires 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.

Arum lily can be hard to control because of its large, hardy root system. Efforts should be repeated over several years to run down the plant’s root system.

 

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 31/03/2020
Fluroxypyr 200 g/L (Staraneā„¢)
Rate: 500 mL - 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 (Staraneā„¢ 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


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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.

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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 2019