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Hindu datura (Datura metel)

Downy Thornapple is an uncommon garden escape in New South Wales, recorded as doubtfully naturalised at Brewarrina. It matters because all parts are poisonous and can pose a serious risk to people and livestock.

Key facts

Type: Weed, herb.

Native to: Probably native to Asia.

Established in: QLD, NSW, WA.

Other names: Datura, Devil's trumpet.

Best time to act: Look for flowering plants in summer and remove or treat them before capsules mature and release seed.

Identification

  • It is a herb that is usually hairless, though it may have sparse, non-glandular hairs.
  • Mature leaves are broad oval to oval, angular, 10–16 cm long and 5–15 cm wide, with slightly wavy to coarsely toothed edges.
  • Its usually double or triple flowers are 14–20 cm long, deep purple outside and pale lavender to white inside, with lobes ending in slender points.
  • The fruit is a deflexed, roughly spherical capsule 3–4 cm long and wide, with numerous blunt, similar-sized spines about 2–5 mm long.
  • It flowers in summer.
  • Look-alike: Other thornapples, including Datura stramonium, can look similar; Downy Thornapple is distinguished by its usually double or triple purple-and-pale flowers and deflexed capsule with numerous blunt spines.

Where it grows

In Australia it is reported as an uncommon garden escape and is doubtfully naturalised at Brewarrina.

Why it matters

  • All parts of the plant are poisonous and may cause serious illness or death if eaten.
  • Its presence can create a poisoning hazard for people and livestock, particularly where plants or seed capsules are accessible.

How it spreads

  • Seeds are contained in the spiny capsules, so movement of capsules, plant material or contaminated soil can spread the plant.
  • Avoid moving soil or plant waste from infested areas unless it has been checked and handled to prevent seed dispersal.

Control options

  • Wear gloves and avoid contact with the plant, especially when removing it, because it is poisonous.
  • For small infestations, remove plants before they set seed, taking care to remove the roots and contain the capsules.
  • Dispose of plant material and seed capsules in accordance with local council or state guidance, and do not spread them in compost or green waste.
  • Where suitable, use a herbicide registered for the site and target plant, following the product label and local advice; revisit the site for seedlings and regrowth, and seek biosecurity advice about reporting.

Hygiene and washdown

  • After working around plants, clean soil and plant material from boots, tools, machinery and vehicles before leaving the site.
  • Do not transport capsules or contaminated soil to clean areas.
  • Inspect and clean vehicles, plant and footwear before leaving an infested area, paying attention to tyres, radiators, belly plates, tracks and floor mats.
  • Wash down at a designated bay where runoff is contained and can be monitored for seedlings.
  • Record each washdown so the client has evidence of clean entry and exit.

Classification by state

  • Australia (national): No national listing. Managed under state and territory law.
  • Queensland: Not prohibited or restricted. Not listed as prohibited or restricted matter in Queensland. Everyone must also take all reasonable and practical steps to minimise its risks (the general biosecurity obligation).
  • New South Wales: Not a priority weed. Not a state or regional priority weed in NSW. The general biosecurity duty applies: anyone dealing with it must prevent, eliminate or minimise the risk it poses.
  • Victoria: Not declared. Not declared under the Catchment and Land Protection Act 1994. Other Victorian laws may still apply.
  • South Australia: Not declared. Not declared under the Landscape South Australia Act 2019. Other laws may still apply.
  • Western Australia: Permitted, not declared. Listed as a permitted organism in WA, so it can be brought in, but it is not a declared pest.
  • Tasmania: Declared weed. Property managers are required by law to control declared weeds, and their import and sale are prohibited.
  • Northern Territory: Declared weed. Weeds Australia lists it as a declared weed in the NT under the Weeds Management Act 2001. Check the NT declared weeds list for its class and what it requires.
  • Australian Capital Territory: Not declared. Not declared under the Biosecurity Act 2023 (ACT). A general biosecurity duty still applies.

Legal obligations

Every state and territory places a duty on landholders and people working on land to prevent the spread of invasive species, such as the general biosecurity obligation in Queensland and the general biosecurity duty in New South Wales. Declarations and control requirements differ between states and local government areas, so check the current official list before work starts.

  • Queensland: Biosecurity Act 2014 (Qld), administered by Biosecurity Queensland (13 25 23)
  • New South Wales: Biosecurity Act 2015 (NSW), administered by NSW Department of Primary Industries and Regional Development
  • Western Australia: Biosecurity and Agriculture Management Act 2007 (WA), administered by the WA Department of Primary Industries and Regional Development

Sources