Species such as fen ragwort and wood calamint are now only found on road verges, sites that are becoming the final refuge of many plants that supply nectar and pollen to the nation’s declining numbers of bees and butterflies.
Birds, bats and insects also rely on plants in verges, with one species, the bird’s-foot trefoil, providing a food source for 160 species of insect alone.
Fen ragwort was found to be hanging on in just one native spot, near a burger van on a roadside in Cambridgeshire, the Plantlife charity reports. Other plants such as sulphur clover, crested cow-wheat and wood bitter-vetch have lost much of their habitats in meadows, pastures or woodlands and are now most frequently found on the side of roads.
According to Plantlife, Britain’s verges are home to more than 700 species of wild plants, one in eight of which are threatened with extinction or heading that way.
Trevor Dines, the charity’s botanical specialist, said: “For too long road verges have been thought of as dull, inconsequential places that flash by in the wing mirror. But these findings underline just how fundamental verges are to the health of wildflowers and the wildlife they support.”
He added: “Sadly, road verges have been woefully disregarded for decades and are increasingly poorly managed for nature.”
Only “genuine management for nature” will safeguard plants that are vulnerable to extinction, Mr Dines said, as he warned that one problem was that many councils now mow road verges earlier in the year. This gives only early flowers a chance to set seed and later plants struggle to survive under the cuttings left behind.
The warning comes despite measures in the Government’s Bee and Pollinator Strategy, announced in November 2014, to give over vast tracts of land to create pollinator friendly habitats. The Highways Agency said then that it planned to rehabilitate 3,475 hectares of grassland to create more species rich swards.
Some verges are effectively fragments of wildflower-rich ancient hay meadows, 97 per cent of which have been lost since the 1930s.
In the Yorkshire Dales and the Forest of Bowland, damaged hay meadows covering an equivalent area of more than 725 Wembley football pitches have been restored by the Yorkshire Dales Millennium Trust’s Hay Time project and Carl Lis, chairman of the Yorkshire Dales National Park Authority, said more could be achieved.
Mr Lis said: “We have done an awful lot but there’s always a lot more to do.
“In terms of roadside verges the local authority do what they can. It’s so difficult as funding isn’t what it used to be.”
TOP TEN MOST THREATENED
Plantlife has revealed the top 10 threatened species growing on Britain’s road verges, as it calls for better road verge management to help protect wild flowers and plants.
They are: fen ragwort, spiked rampion, crested cow-wheat, tower mustard, velvet lady’s-mantle, yarrow broomrape, sulphur clover, wood calamint, Welsh groundsel and wood bitter-vetch.
The charity claimed that simple changes to roadside verge management such as mowing later can have a major difference.