Rare orchids found growing on a spoil tip next to an old coal mine could represent "evolution in progress", according to experts.
Young's Helleborine only grow at two sites in Scotland
The orchids, known as Young's Helleborine, or Epipactis Youngiana, only grow at 10 locations in the UK.
Experts believe they took root at Almond Bing, near Falkirk, almost as soon as the last miners left in the mid-1980s.
Only two sites in Scotland are known to support the rare flowers.
Each of the 10 areas of the UK on which the flower is found are former industrial sites.
Research suggests the species is a newly-developed variety of the more common Broadleaved Helleborine.
The finding could mean that the Broadleaved Helleborine has adapted itself to suit the inhospitable terrain of an old pit bing.
Plant experts working at the bing said the flowers showed evolution in action.
They have harvested thousands of minuscule seeds from the pink plants' green seedpods in an attempt to understand more about them.
Craig Macadam, biodiversity officer at Falkirk Council, said the plant "thrived" in the tough conditions at the bing, next to the former Muiravonside Colliery, which was flooded during the miners' strike of 1985 and later abandoned.
"This particular species is found at less than ten places across the UK - with only this one in Falkirk and another in West Lothian in Scotland," he said.
"The rest are spread across England and Wales."
Half of the seeds have been sent off to labs for further research by the UK Hardy Orchid Society, based at Oxford, while the rest have been replanted in other areas of former colliery bings to examine how they grow.
Mr Macadam added: "They seem to thrive on post-industrial landscapes and Almond Bing is just ideal for that.
"We don't know exactly how they got there, but we think they have been dormant in the soil and when the soil has been disturbed they have grown through the soil.
"The bing is covered in trees and other kinds of growth, but these orchids are unique."
Suzanne Cooper, spokeswoman for leading Plant protection charity Plantlife Scotland, said it was important to monitor rare plants to preserve them for future generations.
She added: "We will be excited to see what happens, both to the seeds being propagated and those that have been sown on site.
"We hope the information we obtain will help Plantlife Scotland to give the right advice about the conservation of these plants here at Almond Bing and other similar sites."