Salvinia is a State prohibited weed
State prohibited weeds are the highest category of declared noxious weeds in Victoria. By definition, they are either not yet in Victoria, or are here in small numbers, where their eradication is still possible.
All sightings should be reported to Agriculture Victoria immediately by calling 136 186 or emailing firstname.lastname@example.org.
Why is it important to report salvinia sightings to Agriculture Victoria?
Salvinia originated in South America and is a problematic weed in North America, Hawaii, the Philippines, South East Asia, PNG, India, Africa and New Zealand. In Australia it is declared as a prohibited weed in all States and Territories.
Salvinia is a floating fern that can quickly form dense mats and completely cover the water surface by doubling in biomass every few days when conditions are suitable. With this rapid growth, it can block waterways, impede irrigation and prevent recreational activities and impact water quality, resulting in the loss of native flora and fauna.
How to identify salvinia
Salvinia has small oval leaves, up to 5 cm long, that grow in opposite pairs on the leaf stem. These floating leaves are green and covered in waxy hairs which make the leaves water repellent.
Leaves of crowded plants are oblong in shape and deeply folded.
The leaf shape varies greatly depending on the growth stage of the plant and if the plant is crowded.
Leaves of isolated plants range from oblong to heart-shaped and lie flat on the water surface.
Submerged leaves look like roots, with short brown hairy stalks ending in hairy filaments that can grow up to 50 cm long.
What should you do if you find salvinia?
If you think you have seen salvinia, please contact Agriculture Victoria immediately on 136 186 or send an email to email@example.com.
Please do not attempt to treat or dispose of this weed yourself. Agriculture Victoria will treat, remove and dispose of salvinia safely, at no cost to the land owner.
Salvinia was introduced to Australia as an ornamental, aquarium plant. It has since been found in waterways in QLD, NSW, NT, WA and in isolated open waterways in regional Victoria, where successful eradication has been achieved.
Salvinia has prolific growth in nutrient rich water when water temperatures are between 20–30°C. Dams can be completely covered by salvinia in one growing season. Therefore it is critical that an effective eradication program be implemented as soon as an infestation is discovered, to prevent linked open water systems from becoming infested, and eradication less viable.
Azolla plants (Azolla spp.) are also small, floating, perennial ferns with long free hanging roots, that are commonly mistaken for salvinia. The key difference is in the leaf shape and colour. Azolla has triangular shaped leaves that become red in colour when exposed to high levels of sunlight.