Lagarosiphon major (Ridl.) Moss
Lagarosiphon is declared under the Catchment and Land Protection Act (1994) as a State prohibited weed. It is an aquatic plant that originates from southern Africa and has become a major weed in New Zealand and parts of Europe. Plants have been found in New South Wales and Victoria, mainly in aquaria and ponds, where they are used for ornament and oxygenation. All known infestations in Australia have been eradicated.
Lagarosiphon looks very similar to other commonly grown plants in aquaria and ponds such as Elodea, Egeria and Hydrilla.
What are State prohibited weeds?
State prohibited weeds either do not occur in Victoria, or are present and can reasonably be expected to be eradicated. State prohibited weeds are the highest category of noxious weeds under the Catchment and Land Protection Act (1994). The Department of Economic Development, Jobs, Transport and Resources (DEDJTR) is responsible for the eradication of State prohibited weeds. The Victorian Government is committed to preventing the introduction of high-risk weeds into Victoria, to protect our environment, economy and social values.
Why is it a problem?
Lagarosiphon is an aggressive fresh water aquatic plant that prefers the cooler waters of the temperate zone, such as Victoria. It chokes still and slow moving water like lakes and dams. It depletes oxygen levels in water resulting in fish kills, and prevents recreational activities like swimming, boating and fishing. Once established it is difficult and costly to eradicate and is easily spread between water bodies by stem and root fragments on boats and trailers.
How to identify lagarosiphon
Lagarosiphon is an aquatic plant that grows submerged,rooted to the floor of the water body or free floating. Stems can grow to 3.5-5.4 m long. It tolerates a range of water conditions but grows best in sheltered, still or slow moving water bodies. It can be confused with other common aquatic plants such as Elodea, Egeria and Hydrilla.
Lagarosiphon usually has stiff, bright green to dark green leaves 5-20 mm in length, arranged in alternate spirals along the length of the stem (not in grouped whorls around the stem like its look-alikes). Female flowers are very small, have three white petals and are visible on the water surface from December to April.
What should you do if you find a lagarosiphon plant?
If you think you have seen a lagarosiphon plant, please contact the DEDJTR by telephoning 136 186 or use the online reporting tool.
Please do not attempt to control or dispose of this weed yourself.