Lagarosiphon

• It is an aggressive perennial submersed aquatic plant with branched, brittle stems up to 5m long.
• Plants can grow surface-reaching mats up to 4m from the bottom of a water body.
• Leaves are stiff, curled backwards and alternately arranged in spiral form.

3D model

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• Inhabits still and slow-flowing water bodies.
• Prefers clear water due to high light requirements.
• In clear water, can live up to 6.5m below the surface.
• Grows well on silty or sandy beds with low nutrient levels.

• Not known to occur in Queensland.

• Under suitable conditions, forms large, surface-reaching mats throughout the year.
• Male flowers break from the plant and float towards female flowers, which remain attached to the stem by long, thin, filament-like tubes.
• Predominantly reproduces from stem fragments in native and introduced ranges.
• Flowering or regeneration by seed has not been observed in Australia.

Environmental

• Invades dams, lakes and streams.
• Affects native fish and waterbirds when growth becomes dense and restrictive.
• Outcompetes native aquatic plants and forms monospecific stands.

Economic

• Interferes with power generation and irrigation infrastructure by blocking intake systems.
• Interferes with recreational activities such as boating, fishing and swimming.

• Mainly spread by humans via boat trailers and fishing gear.
• Also spread by water movement: stems break at a node, float downstream and produce new infestations.

• Find out how farmers can prevent weed spread.
• Find out how gardeners and outdoor enthusiasts can prevent weed spread.

• Before undertaking any preventative or control actions, contact us online, by phone or in person.

Biological control

• No known biological control agents.

• Lagarosiphon is a prohibited invasive plant under the Biosecurity Act 2014. You must not:
  • keep it
  • move it
  • give it away
  • sell it
  • release it into the environment.

If you do any of these, penalties may apply.

• You must not take any action that is reasonably likely to exacerbate the biosecurity threat posed by lagarosiphon.
• You must take any action that is reasonably likely to minimise the biosecurity threat posed by lagarosiphon.
• You must report any sightings immediately using 1 of these methods:
  • Report online.
  • Phone Biosecurity Queensland on 13 25 23.
  • Phone the Exotic Plant Pest Hotline on 1800 084 881.