Police are cracking down on illegal cactus sales across New South Wales, fearing the weed could spread, causing harm to people and animals and rendering farmland useless.
Dozens of plants are prohibited from being sold in NSW, including several cactus species such as Aaron's beard prickly pear, blind or bunny ears cactus and boxing glove cactus.
Those caught selling the plants could be hit with a $1,000 fine or up to $220,000 for businesses found in breach of the Biosecurity Act.
Regional Weeds Co-Ordinator with Hunter Local Land Services Matt Kennedy said the sales were 'quite common', and most people did not realise what they were buying or, in some cases, selling.
"A lot of them will end up being a form of prickly pear, Opuntia, or similar."
Prickly pears were introduced to Australia on the First Fleet and by 1920 had infested more than 23 million hectares across NSW and Queensland.
Mr Kennedy said the 'prickly menaces' could be harmful to pets, native animals and livestock, and could escape quickly.
"Into nearby bushland, reserves and impact the biodiversity on those systems and really take over.
"It'll impact on our agricultural lands where cattle grazing close to the ground, or other herbivores grazing, will eat for example tiger pear, it'll get in its mouth, and it will infect its mouth and hinder the growth of that animal.
How can you tell what you're buying?
Mr Kennedy said it was a case of buyer beware, and people should ask sellers questions online and in person.
"You've just got to check who you're buying the plants from, and if they don't know the botanical name of the plant, then that would raise the first question for me."
"There's also an app."
Mr Kennedy said the joint campaign of NSW CrimeStoppers, Local Land Services and the NSW Department of Primary Industries was more about "public education".
"This campaign is to raise the public attention and to get the public to start nominating people who are selling these plants online because there are just too many for our weeds officers to track."
