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Broad-kernel espartillo (Amelichloa caudata)

This introduced grass is a weed of native grasslands, open forests, grazing land, disturbed sites and waterways, and has spread rapidly in parts of New South Wales and Victoria. It is of particular concern in those states and can be a serious weed of lucerne in its native range.

Key facts

Type: Weed, grass.

Native to: South America.

Established in: NSW, VIC, TAS.

Other names: Espartillo, Speargrass, Chilean Ricegrass, Puna Grass.

Best time to act: Look for flowering stems in spring and late spring or early summer, and remove flowers before seed set.

Identification

  • A long-lived, tussock-forming grass with upright stems 55 to 100 cm tall.
  • Its narrow leaves are 25 to 70 cm long and 1 to 7 mm wide, with small hairs along the margins.
  • The obvious seed-heads are loose, elongated clusters near the top of the plant, usually 15 to 25 cm long.
  • Each seed has a hairy base and a long, twisted bristle-like awn; the seeds are yellow-brown and 2 to 3 mm long.
  • It can also produce greenish seed-heads hidden within the lower leaf sheaths.
  • Look-alike: Narrow-kernel Espartillo (Amelichloa brachychaeta) has narrower grains, 0.9 to 1 mm wide, with more densely hairy seed coats; Broad-kernel Espartillo grains are 1 to 1.4 mm wide and partly hairy.
  • Look-alike: Native speargrasses (Austrostipa species) are similar, but Broad-kernel Espartillo has membranous ligules.

Where it grows

In Australia it occurs in New South Wales, Victoria and Tasmania, in native grasslands, open forests, grazing land, disturbed sites and waterways.

Why it matters

  • It is a weed of native grasslands, open forests, grazing land, disturbed sites and waterways.
  • In Argentina and California it is a serious problem in lucerne pastures, where it reduces yield and interferes with mowing.
  • Young plants are palatable, but adult plants are highly unpalatable to most stock and are not readily grazed.
  • It has spread rapidly in parts of New South Wales and Victoria and is of particular concern there.

How it spreads

  • It spreads only by seed.
  • Awns can attach seeds to stock, wildlife and people, including on wool, fur and clothing.
  • Seeds can also be moved by farm machinery, mud on shoes or hooves, and flowing water.

Control options

  • Winter cropping and repeated cultivation can control it; crop rotation that allows tillage and use of selective herbicides is also effective.
  • In pastures, light stocking and rotational or strip grazing can help maintain pasture competitiveness and slow invasion.
  • Herbicides can help in invaded pastures; grazing down preferred species before spot-spraying or direct application to the weed is one approach. Use registered herbicides according to their labels.
  • Remove flowers before seed set, and remove clumps, dry them and possibly burn them; monitor treated sites for regrowth and new seedlings.

Hygiene and washdown

  • Check and clean machinery, clothing, footwear and gear to remove seeds and mud, as seeds can travel on awns attached to clothing or in mud on shoes and machinery.
  • Avoid moving seed-bearing material or contaminated mud in water, as flowing water can disperse 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: Regional priority in 1 of 11 regions. Regional priority weed in Hunter. 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: Declared pest, notifiable, prohibited. It is a declared pest throughout the ACT. You must report it to ACT Biosecurity. Dealing with it, such as selling, moving or keeping it, is prohibited.

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
  • Tasmania: Biosecurity Act 2019 (Tas), administered by Biosecurity Tasmania

Sources