Rare orchids in Four Marks are potentially under threat from house builders.

Diana Tennyson, a member of Wild Orchid Conservation and Protection (NE Hants), said violet helleborines had been found on the verge at Pooks Hill in Alton Lane.

But she added: “A developer is planning to apply for planning permission to build a housing estate in a field adjacent to the property. Traffic sensors have now also been placed in the lane.”

Orchid enthusiast Stephen Oakes-Monger is publishing a book called In Search Of Wild Orchids, and he contacted Diana about rare orchids he found in Hampshire.

Diana said: “I first encountered him back in August 2012, when he recorded 80 in Blackberry Lane, eight in Telegraph Lane, and mentioned seeing them at Pooks Hill in Alton Lane as well. In The Shrave, along the A31, he counted 81.

“I am sure I have already passed information to the Hampshire Biodiversity Information Centre relating to orchids at Pooks Hill because I recall asking about white posts for the verge.”

Diana said East Hampshire District Council had surveyed trees on the site.

But she felt it was unsuitable for housing: “Anyone checking this site will have noticed that it is a narrow country lane.

“There are major flooding issues in Alton Lane. During heavy rainfall, rain water runs straight down the lane to Five Cross Roads towards Four Marks Primary School, and has often caused problems with access where parking is already hazardous when dropping off and picking up school children.

“Additionally, parents collecting children from the primary school have very few options for safe parking and use the bottom of Alton Lane, where they often alight on the verge.

“If this site were to be approved for a development, this would exacerbate the problem as construction vehicles would require access, and post-development so would all new residents.”