Mexican poppy (Argemone mexicana)


How does this weed affect you?

Mexican poppy is an erect annual herb growing to one metre high, with spiky leaves, bright yellow flowers and globular seed heads. It is poisonous to stock and humans, but is rarely eaten by stock due to its unpalatable bitter yellow sap; however contamination of stock feed with seeds of Mexican poppy may result in poisoning. Seeds can be spread in water, mud, fodder and grain, and on machinery.

Mexican poppy is native to Mexico.

Mexican poppy may be confused with two related species - Argemone ochruleuca, and Argemone subfusiformis, both also commonly called Mexican poppy. Argemone ochruleuca has creamy white to pale yellow flowers and Argemone subfusiformis has flowers similar to Argemone mexicana but with broader petals (2.8-3.3 centimetres wide compared to 1.7-2.5 centimetres wide for Argemone mexicana).

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Herbicide options

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

See Using herbicides for more information.

2,4-D LV ester 680g/L (Estercide® Xtra)
Rate: 800 mL to 1.15 L per ha
Comments: Pastures (non legumes), rights of way and industrial areas.
Withholding period: 7 days
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.

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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

Reviewed 2018