Definition: Generate an appropriate title for the given text. The generated title must be short and include the main topic of the text. The preferred titles are under fifteen words.
Input: The moss, which grows on thatched roofs, was believed to be disappearing because of modern roofing techniques. Richard Lansdown, a moss expert, said: "It seems to favour middle-aged thatch but can appear on a roof four or five years after re-thatching." It has been found in Cornwall, Devon, Dorset, Somerset and Gloucestershire. Moist roofs The National Trust looked at 54 sites and found the leptodontium gemmascens moss on 18 buildings, 10 of which were new sites located in the South West. The trust said the practice of patching up roofs which encouraged the growth of this plant has decreased in popularity, with more people instead opting to have whole roofs replaced. Thatch moss forms dull green patches on roofs and grows up to 1cm tall. Mr Lansdown, who carried out the survey, said: "Recent work suggests that moist roofs close to trees or in the valleys are favoured by thatch moss." The National Trust believes it could be more widespread than previously thought. Matthew Oates, a conservation advisor at the 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. "People living in thatch cottages in southern England may be hosting this moss alongside the more common and obvious mosses."

National Trust finds rare thatch moss at 10 new sites