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Rubber vine (Cryptostegia grandiflora)

A climbing shrub that smothers riparian vegetation across northern Queensland. Its milky sap is poisonous and its wind-blown seed travels far along watercourses.

Key facts

Type: Weed, vine and creeper.

Native to: Madagascar.

Established in: QLD, WA, NT.

Identification

  • Scrambling shrub or vine that climbs up to 30 m into trees.
  • Glossy, dark green opposite leaves; stems exude white milky sap when broken.
  • Large pink to white trumpet-shaped flowers.
  • Paired, angular seed pods up to 12 cm long with silky-tufted seeds.

Where it grows

Riverbanks, gullies, floodplains and pasture in dry tropical Queensland.

Why it matters

  • Smothers and kills riparian trees.
  • Toxic to stock.
  • Restricts access to water.

How it spreads

  • Wind and water carry the silky seeds.
  • Planted as an ornamental in the past.

Control options

  • Basal bark, cut stump or foliar treatment with registered herbicides.
  • Fire is effective on large infestations when planned with follow-up.
  • A rust fungus biological control agent is established.

Hygiene and washdown

  • Avoid getting sap on skin or eyes; wear gloves and eye protection.
  • 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): Weed of National Significance. One of 32 nationally agreed priority weeds, managed through national strategies with all states and territories.
  • Queensland: Restricted matter, category 3. Do not give it away, sell or release it into the environment. 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: Restricted weed. Where it is a restricted weed, trade in it (including the plant, its seed or contaminated material) is prohibited.
  • 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: Declared pest (C2), prohibited. C2 Eradication: present in limited areas and targeted for eradication. It must not be brought into WA (prohibited organism).
  • Tasmania: Declared weed. Property managers are required by law to control declared weeds, and their import and sale are prohibited.
  • Northern Territory: Declared weed, Class A. Class A: to be eradicated. All declared weeds are also Class C, so they must not be brought into the NT.
  • Australian Capital Territory: Declared pest, prohibited. It is a declared pest throughout the ACT. 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.

  • Queensland: Biosecurity Act 2014 (Qld), administered by Biosecurity Queensland (13 25 23)
  • Western Australia: Biosecurity and Agriculture Management Act 2007 (WA), administered by the WA Department of Primary Industries and Regional Development
  • Northern Territory: Territory Parks and Wildlife Conservation Act 1976 (NT), administered by NT Department of Lands, Planning and Environment

Sources