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Narrow kernel espartillo (Amelichloa brachychaeta)

This introduced grass is recorded in New South Wales, where it is known from the North-Western and Central-Western Slopes. It is not currently widespread in Australia, but its seeds readily attach to wool, fur and clothing and can also spread on machinery.

Key facts

Type: Weed, grass.

Native to: South America.

Established in: NSW.

Other names: Epartillo, Achnatherum brachychaetum, Jarava brachychaeta, Stipa brachychaeta.

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

Identification

  • A perennial tussock-forming grass with upright stems 40–100 cm tall.
  • Its leaf blades are thread-like, 0.5–3 mm wide, and rough and hairless, with small hairs along the margins.
  • The upper seed-heads are elongated clusters 10–25 cm long, with widely spaced branches and solitary spikelets.
  • Seeds are yellow-brown, 2–3 mm long, with a hairy coat; additional self-pollinated seeds can form inside both upper and lower leaf sheaths.
  • Look-alike: Broad Kernel Espartillo (Amelichloa caudata) has broader grains, 1–1.4 mm wide, with partially hairy seed coats; Narrow Kernel Espartillo has grains 0.9–1 mm wide with more densely hairy coats.
  • Look-alike: Native Speargrasses (Austrostipa species) can look similar, but Narrow Kernel Espartillo has membranous ligules.

Where it grows

In Australia it is known only from the North-Western and Central-Western Slopes of New South Wales, where it occurs in places such as roadsides, grasslands, stream banks, disturbed sites, waste areas and disused pastures.

Why it matters

  • In Argentina and California it is a serious weed in lucerne pastures, where it reduces yield and interferes with mowing.
  • Although palatable when young, adult plants are highly unpalatable to most stock and are not readily grazed.

How it spreads

  • It spreads only by seed, which can attach to the wool, fur and clothing of stock, wildlife and people.
  • Seeds can also travel on farm or other machinery, in mud on shoes or hooves, and in flowing water.

Control options

  • Winter cropping and repeated cultivation are effective control options, though control is more difficult when the weed invades pastures.
  • Light stock grazing and rotational or strip grazing can help maintain pasture competitiveness and slow invasion.
  • Remove flowers before seed is set; however, seeds can also develop inside the leaf sheaths without cross-pollination, even after mowing.
  • Registered herbicides can be useful; in invaded pastures, grazing can reduce the height of preferred species before direct application or spot spraying, and treated sites should be monitored for regrowth and new seedlings.

Hygiene and washdown

  • Check and clean machinery, footwear and clothing after working in infested areas, as seeds can travel in mud on machinery, shoes or hooves and attach to clothing.
  • 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: 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

Sources