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Tussock paspalum (Paspalum quadrifarium)

Tussock Paspalum has a limited distribution in Australia, occurring mainly around Sydney and in scattered localities along the eastern seaboard. It can rapidly form dense infestations in bushland, displacing native plants, changing fire regimes and providing shelter for feral animals.

Key facts

Type: Weed, grass.

Native to: Uruguay, Paraguay, Brazil and Argentina.

Established in: NSW, VIC.

Other names: Goldentop Grass.

Identification

  • It is a perennial grass that grows in large bluish-green tufts up to 2 m tall.
  • The leaf sheath and blade are mostly hairless, and the blade rolls inwards as it dries.
  • Its flower head is 12–30 cm long, with 15–40 straight branches that slope upwards.
  • The paired spikelets are about 2.5 mm long, arranged in four irregular rows on one side of each branch, and are brown to straw-coloured, often tinged with purple.
  • Look-alike: African lovegrasses (Eragrostis spp.) can have similar-looking seed heads.
  • Look-alike: It can resemble Paspalum (P. dilatatum), but Tussock Paspalum has short white hairs on the upper glume, while P. dilatatum has long silky hairs on the spikelet.

Where it grows

In Australia it occurs mainly in the Sydney region and in scattered localities near Gympie–Maryborough and Townsville in Queensland and near Melbourne in Victoria, often on neglected land alongside roadsides, streams, wetlands and drains.

Why it matters

  • Large, dense clumps can form almost impenetrable walls and dominate other vegetation, including native plants, with serious implications for biodiversity.
  • Mature clumps, alive or dead, are highly combustible and can change fire regimes.
  • The clumps provide shelter for feral cats and rabbits.

How it spreads

  • It spreads through rhizomes and seeds, forming dense infestations; rhizomes send up suckers and seeds can establish new plants nearby.
  • Seeds can be carried by water, animal fur, clothing, mud-encrusted boots, vehicle tyres and mowing machinery.
  • Downhill water can carry seeds from disturbed edges into native bushland, and sticky seeds can transfer to animals, people and machinery.

Control options

  • A common method is to brush-cut the plant and spray the regrowth with registered herbicides.
  • Some local councils have had success spraying without brush-cutting; follow-up is almost always needed because plants may resprout a year or more after treatment.
  • Hand removal is possible for scattered plants or small infestations, particularly in sandy or friable soil.
  • Warringah Council trialled burning clumps successfully, but in Argentina fire is also used to increase the plant’s growth and nutrient value.

Hygiene and washdown

  • Seeds can travel on boots, clothing, vehicle tyres and mowing machinery, as well as in mud and water.
  • Clean mud and plant material from boots, vehicles and machinery before moving from an infested area to an uninfested site.
  • 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: Not listed. Not found in the Western Australian Organism List. Check with DPIRD before moving or keeping it.
  • 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.

  • New South Wales: Biosecurity Act 2015 (NSW), administered by NSW Department of Primary Industries and Regional Development
  • Victoria: Catchment and Land Protection Act 1994 (Vic), administered by Agriculture Victoria

Sources