Lagarosiphon: declared pest

Page last updated: Saturday, 28 September 2019 - 12:00pm

Please note: This content may be out of date and is currently under review.

Lagarosiphon (Lagarosiphon spp.) is a declared pest in Western Australia (WA). This article describes the nature of the plant with links to requirements land owners/occupiers must adhere to and pest control methods.

Form: aquatic — perennial

Status: not present in WA

A submerged rhizomatous perennial plant native to South Africa. Grows readily from shoot fragments.


Stems: Branched up to five metres long.

Leaves: Alternate, bending back, crisp to two centimetres long. Leaves grow in a spiral arrangement and not in groups or whorls.

Agricultural and economic impact

An environmental weed. This aquatic weed forms dense mats of vegetation several metres thick at or just below the water surface, blocking light penetration, out-competing and displacing native water plants and affecting associated populations of aquatic invertebrates. Severe infestations can affect the use of waterbodies for recreational activities such as swimming, boating and fishing.

Declared pest category

The Western Australian Organism List (WAOL) contains information on the area(s) in which this pest is declared and the control and keeping categories to which it has been assigned in Western Australia (WA). Search for lagarosiphon in the WAOL. using the scientific name Lagarosiphon spp.

Requirements for land owners/occupiers and other persons

Requirements for land owners/occupiers and other persons if this pest is found can be sourced through the declared plant requirements link.

Search > detect > report

MyPestGuide™ Reporter
via app or online
(Select 'Send report to MyWeedWatcher' from menu)

Pest and Disease Information Service (PaDIS)
+61 (0)8 9368 3080

Control method

Control methods for this declared plant can be found through the lagarosiphon control link.

Contact information

Pest and Disease Information Service (PaDIS)
+61 (0)8 9368 3080
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