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Gallon's curse (Cenchrus biflorus)

Gallon's curse is an introduced annual grass that can grow rapidly and form dense infestations. Its spiny burrs spread readily and can injure people and stock.

Key facts

Type: Weed, grass.

Native to: Northern Africa and India.

Established in: QLD, WA, NT.

Best time to act: Look for and treat plants while actively growing and before seedheads emerge; flowering is reported from April to August.

Identification

  • An annual, branched and slender grass that can grow up to 90 cm tall.
  • Leaves are alternate, 2–25 cm long and 2–7 mm wide, with an open sheath and a fringe of hairs at the leaf base.
  • Seedheads are cylindrical, 2–15 cm long and 9–12 mm wide, and can be green, yellow or brown.
  • Burrs have spines 5–8 mm long fused at their lower third into a small dish or narrow cup; longer spines have downward-pointing barbs.
  • Seeds are oblong or roundish, 1.1–1.3 mm long, and are shed enclosed within the burr.
  • Look-alike: Other Cenchrus grasses may look similar; check the burr structure and seek identification advice if uncertain.

Where it grows

In Australia it grows among native pastures in the western Kimberley, in Queensland's Gulf region and throughout the Northern Territory, mainly in areas with monsoonal summers.

Why it matters

  • It can grow rapidly and form dense infestations under suitable conditions.
  • Spiny burrs can injure people and stock.
  • Burrs readily attach to clothing and animals, allowing the weed to spread into new locations.

How it spreads

  • Plants reproduce by seed only, with seeds enclosed and shed within the burr.
  • Burrs attach readily to clothing and animals and can be carried to new locations.

Control options

  • Prevent seeding and reduce the seed bank using a combination of control methods and pasture management.
  • For individual plants and small infestations, remove plants by hand or hoe, removing as much of the root system as possible; treat seedlings before seedheads emerge.
  • Use only herbicides registered for Cenchrus species, applying them to actively growing plants before seedheads emerge and following the product label and any permit conditions.
  • Monitor treated areas and repeat control as new seedlings emerge; report suspected new infestations to the relevant state or territory biosecurity agency or local weeds officer.

Hygiene and washdown

  • Check and remove burrs from clothing, boots and gear, and inspect animals before moving away from an infested area.
  • Clean vehicles and machinery after working in infested areas to avoid carrying burrs to new sites.
  • 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: Not declared. Not a declared weed in Tasmania. Other laws may still apply.
  • Northern Territory: Not declared. Not on the NT A to Z weed list, and Weeds Australia does not list it as declared in the NT. Check the NT declared weeds list before moving or planting it.
  • 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)
  • Western Australia: Biosecurity and Agriculture Management Act 2007 (WA), administered by the WA Department of Primary Industries and Regional Development
  • Northern Territory: Territory Parks and Wildlife Conservation Act 1976 (NT), administered by NT Department of Lands, Planning and Environment

Sources