A countryside-lover’s stand against an invasion of outlawed onions has been backed by a botany boffin – who says anyone encouraging them to grow could end up in a cell.

Lois Kelly is fighting to halt the spread of aggressive Alium triquetrum, which she says has left bluebells in beauty spots like The Byes in a beleaguered state.

She has warned townsfolk not to be fooled by the invasive wild onion’s pretty appearance – as its ‘horrible’ smell is a giveaway to its true nature.

Retired business studies teacher Lois, 66, of Hillside Road, Sidmouth, felt she was fighting a lone battle in tackling the blight.

However, the district council is now investigating and Lois has received support from the Natural History Museum.

Botanist Professor Fred Rumsey, of the museum’s Centre for UK Biodiversity, confirmed to her that the wild onion is banned – and anyone caught promoting its growth could be jailed or fined.

He also warned that ‘equally problematic leeks’ are also on the march.

Lois says the ‘aggressive and invasive’ wild onion has taken hold in The Byes and decimated its bluebell population.

The Sidmouth resident of 27 years, who first raised concerns in 2014, said: “The leaves look a bit like bluebell leaves and initially you might think they are whitebells.

“Do not be fooled, they smell horribly oniony.

“By tackling these invaders, you will save our lovely bluebells, which are otherwise pushed out by wild onions.

“I implore everyone to dig it up - but compost it into a sealed plastic bag and never into your normal compost.”

Lois has written to East Devon District Council (EDDC), which manages The Byes, on the matter.

A spokeswoman for the authority told the Herald: “Our StreetScene team is currently conducting an investigation, which is likely to take a couple of weeks.”

Prof Rumsey told Lois: “Many people share your concern over this aggressively invasive plant, which is currently being assessed by the Non Native Species Secretariat, but which is already listed on Schedule 9 of the Wildlife and Countryside Act, 1981.

“It is illegal to plant or otherwise cause to grow in the wild any plant listed in Schedule 9.

“It has long been present in the milder far South West but, with climate change, has greatly extended its British range. The related few-flowered leek [Allium paradoxum] is equally problematic, but more of a problem in eastern England.”

He added that magistrates could impose a maximum penalty of a £5,000 fine and/or six months’ imprisonment on offenders. In more serious cases, a crown court judge could hand out an unlimited fine and two years in prison.