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Mikania vine (Mikania micrantha)

Mikania Vine is a serious weed in parts of the Pacific and Asia and has the potential to become a major pest in the Queensland Wet Tropics and other humid parts of northern Australia. It can rapidly smother crops and native vegetation, threatening agriculture and natural ecosystems.

Key facts

Type: Weed, vine and creeper.

Native to: Central and South America.

Established in: QLD.

Other names: Mile-a-minute, American Rope, Chinese Creeper.

Best time to act: Flowering occurs mostly from late autumn through early spring, providing a period when the plant may be easier to detect.

Identification

  • A branched, slender-stemmed perennial vine with ribbed stems that can grow to 6 m long.
  • Heart-shaped or triangular leaves grow in opposite pairs and are 4–13 cm long, with three prominent veins.
  • Small greenish-white or white flower-heads, 3–6 mm long, grow in branched clusters and have no obvious petals.
  • Black, linear-oblong seeds are 1.5–2 mm long and topped with 30 or more fine white bristles.
  • Look-alike: Old Man's Beard has opposite leaves, but they are compound, and its white or greenish-white flowers have four obvious sepals.
  • Look-alike: Climbing Groundsel has alternate simple leaves and relatively large yellow flower-heads with prominent ray florets.

Where it grows

In Australia it is naturalised in Far North Queensland, including Ingham, Bingil Bay and Speewah, and on Christmas Island.

Why it matters

  • It climbs and twines over crops, bushes, trees and other supports, cutting out light and smothering or killing plants.
  • It competes for water and nutrients, and is believed to release substances that inhibit the growth of other plants.
  • It is a major environmental weed overseas and could damage agriculture and native vegetation in northern Australia.
  • Known infestations abut rainforests in the Wet Tropics World Heritage Area, which could be threatened if the weed spreads.

How it spreads

  • Plants produce tens of thousands of fine seeds that can be dispersed by wind, clothing, animal hair, machinery or water.
  • Stems can root at the nodes, and cultivation can break up runners and move viable stem pieces.
  • A plant may cover more than 25 square metres within a few months and produce as many as 40,000 viable seeds a year.

Control options

  • Mikania Vine is targeted for national eradication in Australia, with programmes mapping and monitoring its distribution and coordinating eradication activities.
  • Mechanical control is difficult because the plant produces many viable seeds and new plants can grow from tiny stem fragments.
  • If you find the plant, contact your local council pest management or environment officer, or the relevant natural resources officer, for advice on safe removal; incorrect treatment can make the problem worse.

Hygiene and washdown

  • Avoid moving seeds or stem fragments on clothing, boots, gear or machinery, and clean equipment before leaving an infested site.
  • Do not move plant material in water or during cultivation, which can disperse seeds or viable stem pieces.
  • 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): National weed eradication program. Targeted for eradication under the nationally cost-shared National Tropical Weeds Eradication Program. Report any sighting straight away. National priority exotic pest. On the National Priority List of Exotic Environmental Pests, Weeds and Diseases, so any new detection should be reported straight away.
  • Queensland: Restricted matter, categories 2, 3, 4, 5. Report it to Biosecurity Queensland within 24 hours; do not give it away, sell or release it into the environment; do not move it; do not keep it. Everyone must also take all reasonable and practical steps to minimise its risks (the general biosecurity obligation).
  • New South Wales: Prohibited matter. It is an offence to deal with it, and you must notify NSW DPIRD as soon as you become aware of it.
  • 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: Declared pest (C1), prohibited. C1 Exclusion: to be kept out of WA, or out of the parts of WA where it is not established. Report any sighting to DPIRD. It must not be brought into WA (prohibited organism).
  • Tasmania: Not declared. Not a declared weed in Tasmania. Other laws may still apply.
  • Northern Territory: Declared weed. Weeds Australia lists it as a declared weed in the NT under the Weeds Management Act 2001. Check the NT declared weeds list for its class and what it requires.
  • 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)

Sources