A group of well-meaning Girl Guides caused a public health scare after planting potentially-deadly flowers in a public park - as part of a BBC Countryfile project.
Council groundsmen were called in to clear the toxic corncockles after being alerted by amateur photographer Mike McKee, who was drawn to their unusual purple petals.
They were planted by Guides trying to do a good deed by sowing seeds in Royal Wootton Bassett, Wilts., as part of campaign by Countryfile to encourage wild flowers.
The plant was once believed to be extinct in Britain and just a pinch of the seeds - around 3g - is enough to kill a human or a HORSE.
Mike said: "I had absolutely no idea what they were at first - I just saw them there and they looked a bit different.
"I looked in my flower book and it said these were scant and very rare, so I did a bit more research on them. When I Googled them I found out they could be deadly.
"There are probably other places around here where they have been planted, and people will just walk past without noticing a thing. It only gets really nasty if you touch them."
The Corncockle is a dainty pink or purple flowering plant originally from the European wheat fields.
It was a very common weed in the 19th Century growing continuously side by side to the wheat.
Every part of the plant is poisonous and contain glycoside githagin and agrostemnic acid.
Coming into contact can cause severe stomach pain, vomiting, diarrhoea, dizziness, weakness, slow breathing and even death.
The Royal Horticultural Society says the flower is now ''very rare'' in Britain but warns against picking or even touching it.
The rogue batch were planted in Jubilee Park, Royal Wootton Bassett, by the 2nd Royal Wootton Bassett Guides in May.
They carried out the planting as part of a BBC Countryfile 'Grow Wild Scheme' encouraging people to grow wild flowers across the country.
A plaque next to the spot proudly reads: "Wild flowers sown, with thanks to the Countryfile GROW WILD SCHEME, by 2nd Royal Wotton Bassett Guides, May 2014."
Royal Wotton Bassett Town Council even posted pictures on their Facebook page to thank the guides for their help and to update them with their progress.
But after being alerted by Mike on August 14th contractors quickly moved in to cut the plants, before they could seed, in an attempt to remove them completely from the area.
Mike said: "They were thought to be extinct, but I believe the Royal Horticultural Society have been giving them in packets to Countryfile, who in turn have been distributing them throughout the UK.
"A lot of people want to see wild flowers back again but they don't realise exactly what is in a packet of mixed seeds."
The corncockle is an incredibly rare flower that originates from other parts of Europe, and is believed to have been brought into England by Iron Age farmers.
At one time, most fields would have been filled with the poisonous flower, but modern agricultural methods and weed-killers have all-but wiped it out.
Despite its evil nature, the plant was used for generations in folk medicine, and even receives a mention in Shakespeare's Coriolanus.
The stiffly erect plant grows up to 3ft tall, and is covered with fine hairs - which can cause skin irritation if touched.
Its poison was discovered centuries ago, when doctors thought it could have medicinal properties, and would experiment on patients and animals.
The plant was believed to be completely extinct in the United Kingdom until 2014, when a single specimen was found growing in Sunderland.
They can grow in various places such as fields, roadsides, railway lines and wasteland.
It is believed around 230,000 packets of seeds were sent out to the public as part of Countryfile's Grow Wild campaign.
The BBC programme worked with the famous Royal Botanic Gardens in Kew, London, to promote the seed packets during one episode of the programme.
Keen gardeners received the plants, native to their region, in March, and after planting they finally began to bloom this summer.
But, since then alarmed members of the public have been reporting sightings of the highly-toxic plant.
In July Nigel Crooks discovered the plant in his garden in Wroughton, near Swindon, Wilts.
He said: "I was gobsmacked. My partner was at work and she was on a coffee break reading the newspaper and she saw a photo of the flower they found in Sunderland.
"She rang me and said it looked like the ones we had in the garden.
"I googled the story and it turns out the plant is poisonous and it can cause various illnesses and even death.
"I planted them and looked after them diligently. I thought they would be ideal for me to be a bit more green and to encourage butterflies to come.
"From the research I did, the seeds may have lain dormant. I just did it to get regional flowers but now they may be toxic."
Just a week later Gwilym Roberts, of Rhostryfan, north Wales, discovered he too had unwittingly cultivated the flower.
He told his local paper: "I'm extremely concerned. I'm not blaming anyone, that's not the case. My concern is if they spread.
"Advice on the internet tells people not to touch them. I also suffer with heart problems and have three grandchildren so we need to get rid of them somewhere."
At the time Professor Monique Simmonds, director of the Kew Innovation Unit, assured gardeners that the plants are not high risk.
She said: "This plant, like many we have in our gardens, does contain compounds that can be toxic if eaten in large amounts or eaten frequently over a period of time.
"The toxic compounds are in higher concentrations in the seeds, which are hard and very bitter. If eaten by a child, the child would most likely be sick or complain of a stomach ache.
"There is no evidence that eating a few seeds would cause acute toxicity."
Guy Barter, Chief Horticultural Advisor to the RHS, added: "Like many garden plants, corn-cockle (officially called Agrostemma githago) is potentially harmful especially if consumed.
"Merely touching this plant is a very low risk indeed. We know of no instances of harm occurring from this plant in gardens, but in historical times cases of poisoning occurred from consuming contaminated bread.
"Modern agricultural practices have eliminated it from farm crops. The actual risk of harm is extremely small."