Alligator weed (Alternanthera philoxeroides) can be mistaken for a vegetable but is a State prohibited weed which has been found mostly growing in suburban backyards in Melbourne, with a few infestations in Bendigo and Warragul.
Agriculture Victoria leading biosecurity officer Emily Hill said State prohibited weeds (SPWs) are the highest category of declared noxious weeds in Victoria.
“Alligator weed is native to South America and is regarded as one of the worst weeds. It is a declared noxious weed in all states and territories of Australia because of the harm it can cause to the economy and environment,” Ms Hill said.
“Alligator weed is a particularly hard weed to eradicate because it grows rapidly both on land and in water. It can grow from plant fragments spreading from a parent infestation to produce new infestations downstream.
“Mats of alligator weed can cover an extensive area, impact on irrigation and recreational activities, displace local native flora, damage habitat for native animals, clog up drains and other infrastructure and block water flow.
“On land it can be spread by mowing or sharing plants and can quickly invade your yard, making a mess of backyard gardens, smothering other plants and spreading to congest waterways.
Alligator weed can be mistaken for the vegetable Mukunuwenna, or sessile joyweed (Alternanthera sessilis), which looks similar and has short, round leaves.
“It is unsafe to eat as it accumulates heavy metals from the soil.”
Agriculture Victoria is responsible for eradicating alligator weed from all land in Victoria and has been working closely with local authorities, land managers and community groups to eradicate the plant.
“Please don’t attempt to treat or dispose of this weed yourself. Agriculture Victoria will treat, remove and dispose of alligator weed safely, and at no cost to the landowner,” Ms Hill said.
You can find more about alligator weed or other State prohibited weeds online.