The chef and TV presenter said in a magazine article that the weed henbane, also known as stinking nightshade, made an excellent addition to summertime meals.
There was plenty of it, it grew locally and was used by the ancient Greeks and the Arabs for its anaesthetic properties.
Er, not quite.
Henbane, or Hyoscyamus niger, is toxic and can cause hallucinations, convulsions, vomiting and in extreme cases death.
Worrall Thompson, who was discussing his passion for organic foods, had confused the plant with another of a similar name.
The magazine "Healthy & Organic Living" printed an urgent warning: "Henbane is a very toxic plant and should never be eaten. As always, check with an expert when foraging or collecting wild plants."
Henbane, a close relative of deadly nightshade, was used by Dr Crippen to kill his wife in 1910, and is thought to have been the main ingredient in the poison Romeo took in Shakespeare's play "Romeo and Juliet."
The chef had intended to refer to fat hen, a weed rich in vitamin C, that is edible, media reports said.
It too can be harmful because of its high level of nitrates, but cases of poisoning are rare, Garden Organic said on its website.
Worrall Thompson was reported in the media as saying the confusion had been "a bit embarrassing."
"There have been no reports of any casualties," he said.
"Please do pass on my apologies."