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Yellow burrweed (Amsinckia spp.)

Yellow burrweed is a declared weed in South Australia and can reduce crop yields and pasture productivity. It can also contaminate grain and wool, and is toxic to livestock when eaten in significant quantities.

Key facts

Type: Weed, herb.

Native to: North and South America.

Established in: QLD, NSW, ACT, VIC, TAS, SA, WA, NT.

Other names: Fiddle-neck.

Best time to act: Look for rosettes in winter and flowering stems in late winter and spring, and hand-pull or cultivate plants before they flower.

Identification

  • An erect, bristly annual herb, usually 20–70 cm tall.
  • It develops a basal rosette in winter, followed by upright flowering stems in late winter and spring.
  • Its narrow leaves are rough and hairy, with smaller alternate leaves along the stems.
  • Small, bright yellow, trumpet-shaped flowers about 5–10 mm long grow along one side of a curved, coiled spike.
  • When mature, the bristly fruit breaks into four rough, hard nutlets.

Where it grows

In southern Australia it occurs as a weed in cropping areas, pastures, roadsides and disturbed land.

Why it matters

  • It competes with cereals and pastures for nutrients, light and moisture, reducing crop yields and pasture productivity.
  • Seeds and plant fragments can contaminate grain and wool, lowering product quality.
  • The plant is toxic to livestock and can cause liver damage when eaten in significant quantities.
  • Dense infestations can affect both cropping and grazing enterprises.

How it spreads

  • It spreads only by seed, which can be transported in contaminated grain, hay or fodder and on machinery.
  • Seeds can attach to wool, fur or clothing, or pass through livestock and birds.
  • Road maintenance and soil movement can also spread the seeds.

Control options

  • Prevent seed production and reduce the soil seedbank through consistent control over several seasons.
  • Hand-pull or cultivate small infestations before flowering.
  • Use selective, registered herbicides in crops and pastures when plants are young, following the product label.
  • Maintain competitive pastures or crops to suppress establishment, as the weed thrives in bare or disturbed ground.

Hygiene and washdown

  • Clean machinery when moving between areas, and avoid moving contaminated hay, fodder or grain.
  • Seeds can also travel on clothing, wool and fur, so check these for attached seeds.
  • 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: Restricted weed. Where it is a restricted weed, trade in it (including the plant, its seed or contaminated material) is prohibited.
  • South Australia: Declared plant. Depending on the declaration, it can be an offence to move it on public roads or sell it, and landowners may be required to control it on their land.
  • Western Australia: Not listed. Not found in the Western Australian Organism List. Check with DPIRD before moving or keeping it.
  • Tasmania: Declared weed. Property managers are required by law to control declared weeds, and their import and sale are prohibited.
  • Northern Territory: Check NT list. There is no NT weed profile for it. Check the NT declared weeds list for its current status.
  • 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
  • Australian Capital Territory: Biosecurity Act 2023 (ACT), administered by ACT Biosecurity
  • Victoria: Catchment and Land Protection Act 1994 (Vic), administered by Agriculture Victoria
  • Tasmania: Biosecurity Act 2019 (Tas), administered by Biosecurity Tasmania
  • South Australia: Landscape South Australia Act 2019 (SA), administered by the regional landscape board
  • 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