National Trust Reveals Rare Thatched Moss Found on New Sites in Southern England

SWINDON, England, Oct. 20 /PRNewswire/ -- The National Trust has reported that a rare and distinctive thatch moss, thought to have been on the verge of disappearing because of modern thatching techniques, has been discovered at ten new sites and mostly on buildings owned by the National Trust.

Before the latest discoveries, thatch moss, Leptodontium gemmascens, was only known to exist at a handful of sites in southern England.

Matthew Oates, Nature Conservation Adviser at the National Trust, said: "This survey shows that this endearing and harmless little moss has a real future and that it may be more widespread than we first thought."

The moss was first discovered by experts in 1845 but its distribution was thought to have dwindled in recent years as the nature of thatching changed course.

The traditional approach to thatching encourages the growth of thatch moss as it involved 'patching' sections of the roof; but modern demands for a uniform 'chocolate box' appearance now means that the entire top coat is invariably replaced.

This has helped to hasten its demise and restrict it to only a few hotspot sites in southern England.

Before the survey was carried out this year by a Bryologist (a moss expert) the thatch moss had only been found at eight sites in recent years, including Alfriston Clergy House in East Sussex, the first ever built property acquired by the National Trust back in 1896.

Four of the newly recorded sites, found on buildings owned by the National Trust, had more than 1,000 plants on the thatch, including the martyr's memorial shelter at Tolpuddle in Dorset and a cottage at Blaise Hamlet in North Bristol.

The National Trust shop at Selworthy in north Somerset had more than 3,000 plants on its thatched roof, which represents the largest known population of thatch moss anywhere in the world.

Richard Lansdown, the moss expert who carried out the survey, commented: "Recent work suggest that moist roofs close to trees, or in valleys, are favoured by thatch moss.  It seems to favour middle aged thatch but can appear on a roof four or five years after re-thatching."

Thatch moss is a very small moss which forms dull-green patches up to 1cm tall when it grows.  It has also been found on grassy heaths in Hertfordshire and Norfolk.

The moss has tiny leaves shaped like spears with reproductive structures called gemmae at their tips which disperse to help spread the moss.  This is unique among British mosses.

Matthew Oates continued: "People living in thatch cottages in southern England may be hosting this moss alongside the more common and obvious mosses.  We're keen to find out where else thatch moss might be found beyond the known National Trust sites."

Details and images of what the moss looks like can be found on the National Trust website and thatch cottage owners or tenants can send in pictures of suspected thatch moss found on their roofs to help in the quest to build up a distribution map for the moss.

The survey was funded by Natural England to help monitor existing populations of the moss and look for possible new sites.

About the National Trust:

The National Trust cares for 300 inspiring historic houses and gardens across England, Wales and Northern Ireland. From former workers' cottages to the most iconic stately homes, and from mines and mills to theatres and inns, the stories of people and their national heritage are at the heart of everything it does. The National Trust also offers volunteering opportunities, wedding venues, days out and campsites.

SOURCE The National Trust