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Texas needle grass (Nassella leucotricha)

Texas needle grass can form dense infestations in pastures, native grasslands and woodlands, displacing desirable plants and reducing grazing value. Its sharp seeds can injure livestock and downgrade wool, hides and carcasses, and it has the potential to affect 4.8 million hectares across Australia.

Key facts

Type: Weed, grass.

Native to: Texas and Oklahoma in the United States, and central Mexico.

Established in: ACT, VIC, TAS, SA.

Other names: Texas Needlegrass, Texas Wintergrass.

Best time to act: Flowering begins in early spring and seed production is abundant in summer, but flowering and seeding can occur at other times in favourable conditions.

Identification

  • A long-lived, upright tussock grass that grows about 1 to 1.5 metres tall.
  • Its leaves are about 30 centimetres long and 5 millimetres wide, and most are clustered near the base.
  • Flower heads are contracted panicles up to 25 centimetres long, with many spikelets.
  • The pale-brown to purple seeds have a long, twice-bent awn and a collar-like corona where the awn joins the seed.
  • It can be difficult to identify without seeds; the plant also produces stem seeds at the base and in stem joints.
  • Look-alike: It can be confused with native speargrasses (Austrostipa species) and tussock grasses (Poa species); introduced Nassella grasses have a membranous ligule, while native species either lack one or have a ligule fringed with hairs.
  • Look-alike: Chilean needle grass (Nassella neesiana), lobed needle grass (Nassella charruana) and cane needle grass (Nassella hyalina or Nassella formicarum) also have a corona, so expert identification may be needed.

Where it grows

In Australia it is recorded in South Australia and Victoria, including the Fleurieu Peninsula and central Victoria, especially north-western Melbourne, and favours open, sunny areas.

Why it matters

  • Dense infestations displace desirable pasture plants and native grasses and forbs, reducing biodiversity and stock carrying capacity.
  • The plant is unpalatable and has low feed value, and its masses of flower stalks provide little leaf material during warmer months.
  • Sharp seeds can injure livestock, including their eyes and faces, and penetrate wool, skin and muscle, causing infection and downgrading wool, hides and carcasses.
  • It is considered one of Australia’s worst weeds of native grasslands and pasture.

How it spreads

  • Seeds attach to livestock fleece and coats, hooves, clothing, vehicles and machinery, and can be carried in fodder, grain and hay.
  • Mowing and earth-moving equipment can spread seed along roadsides and grassy areas; stem seeds can also be spread by these methods.
  • Seed can move in water or soil, and buried seed may remain dormant for several years before germinating after soil disturbance.

Control options

  • For isolated plants or small patches, dig out the whole plant; first cut and bag any flowering heads or stem seeds, then destroy the plant.
  • For established infestations, combine suitable approved methods such as herbicide treatment, cultivation, crop rotation, pasture sowing and grazing management.
  • Spot spraying can treat individual plants and small infestations; seek current advice on registered herbicides and application methods from the relevant state or territory agency or local council.
  • Mowing during peak flowering can reduce seed set, but follow-up mowing may be needed as plants can re-flower within two to six weeks; clean equipment and dispose of clippings appropriately.

Hygiene and washdown

  • Check machinery entering the property, and wash vehicles and machinery in one designated area so any germinating seeds can be followed up.
  • Clean clothing and equipment after working in infestations, and do not buy hay, stock feed, crop seed or pasture seed from infested 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: 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: 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.

  • 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

Sources