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Leather leaf sedge (Carex buchananii)

Leather leaf sedge is an introduced ornamental plant and a declared weed in Tasmania, where no populations are known. It can compete with desirable plants, form dense infestations, reduce pasture productivity and alter natural ecosystems.

Key facts

Type: Weed, herb.

Native to: New Zealand.

Established in: .

Other names: New Zealand leather leaf sedge, Carex buchananii.

Best time to act: Search year-round because seeds can germinate at any time, and remove plants before seed heads can disperse seed.

Identification

  • It is a perennial, grass-like herb that grows to about 50 cm tall.
  • Its leaves emerge from the base and are often reddish brown.
  • Flowers grow in cylindrical spikes.
  • It can be difficult to distinguish from native sedges.
  • Look-alike: Native sedges can be difficult to distinguish from New Zealand sedges; seek expert identification if uncertain.

Where it grows

In Tasmania, it has been recorded in amenity plantings and the nursery trade, but no populations are known there.

Why it matters

  • It can compete aggressively with desirable plants and form dense infestations.
  • Infestations can reduce pasture productivity and alter natural ecosystems.
  • Its use in ornamental plantings can create a risk of spread.

How it spreads

  • It spreads by seed and rhizomes, which are underground stems.
  • Spread can occur during road works, slashing, and track construction or maintenance.
  • Ornamental plants pose a significant spread risk.

Control options

  • Remove isolated plants by hand pulling or digging, taking care to remove all rhizome material.
  • Bag and remove seed heads, and avoid slashing because it can spread seed and worsen an infestation.
  • For herbicide options, contact Biosecurity Tasmania and use only products registered for the target and site, following the label.
  • Monitor treated sites for regrowth and seedlings; report suspected plants in Tasmania to Biosecurity Tasmania on 03 6165 3777.

Hygiene and washdown

  • Clean soil and plant material, including seeds and rhizome fragments, from boots, vehicles and machinery after working in an infested area.
  • Contain and dispose of removed material so it cannot spread to clean sites.
  • 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: Check NT list. There is no NT weed profile for it. Check the NT declared weeds list for its current status.
  • 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.

Sources