Biosecurity Spotters logo

Feathertop (Cenchrus longisetus)

Feathertop is an introduced grass that can take over pastures and compete with desirable pasture plants, reducing grazing area. It is also unpalatable to stock, can contaminate wool and may invade degraded roadside and riparian vegetation.

Key facts

Type: Weed, grass.

Native to: Eritrea, Ethiopia, Somalia and Yemen.

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

Other names: Long-style Feather-grass, Longstyle Feather Grass, White Foxtail Feather Grass, Purple Squirreltail Grass.

Best time to act: Look for new shoots in spring and summer, and treat with herbicide while plants are actively growing; flowering occurs in late summer and seeds mature in March and April.

Identification

  • It forms dense, tufted clumps and grows up to 70 cm high, with stems that can reach 90 cm.
  • Its flat, ribbed green or blue-green leaves are up to 30 cm long and 2–6 mm wide.
  • The pale greenish to cream flower head is sometimes tinged with purple, spike-like, branched and feathery, and measures 3–12 cm long.
  • Whitish-green, cream or occasionally purplish spikelets occur in groups of 1–5, surrounded by unequal, feather-like bristles 3–7 cm long.
  • When mature, clusters of spikelets fall as units with their bristles.
  • Look-alike: Other grasses with spike-like, feathery flower heads can look similar; Feathertop has bristles at least three times longer than its spikelets, while most similar species have bristles only a little longer.

Where it grows

In Australia it occurs in all states and the ACT, mostly in urban areas and disturbed soils such as gardens, roadsides, footpaths, creek banks, degraded pastures and neglected areas.

Why it matters

  • It is unpalatable to livestock and can spread through pasture, competing with desirable plants and reducing grazing area.
  • It can take over lawns, vineyards, roadsides, railways, rivers, streams and creeks, as well as open and degraded areas.
  • It can occupy degraded roadside vegetation and invade riparian vegetation, replacing native and desirable species.
  • Around Inverell in New South Wales, it contaminates wool.

How it spreads

  • Cultivation and road grading can disperse rhizome fragments; rhizome growth also enlarges and thickens existing colonies.
  • Seeds are less important for spread because seedlings rarely establish successfully, but bristles can attach to animals, clothing and bags.
  • Spikelets may also move in water and wind, including air currents from passing vehicles, or in dumped garden waste.

Control options

  • Cultivation must be thorough and repeated regularly to remove all rhizome fragments.
  • Hand weeding with tools is not recommended for established plants; it may be suitable for young plants if the underground rhizomes can also be removed.
  • Apply registered herbicides by rope wick or spot spraying while the plant is actively growing, following product directions.

Hygiene and washdown

  • Check and clean clothing, bags, vehicles and machinery to remove attached spikelets and bristles before moving to another site.
  • Avoid moving contaminated garden waste or soil containing rhizome fragments to new 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: 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)
  • 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

Sources