Long-leaved thread moss (Bryum neodamense)

Long-leaved thread moss
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Long-leaved thread moss fact file

Long-leaved thread moss description


Long-leaved thread moss  is one of the easiest of the Bryum group of mosses to identify. It grows in tufts, is a reddish-green in colour, and the leaves are rather curled in appearance, especially when they dry out.

Height: up to 10 cm

Long-leaved thread moss biology

This rare moss is now found in only two of its former UK sites, the main one being the dune system along the Sefton coast in Lancashire, centred on Ainsdale National Nature Reserve (NNR). Coastal dune systems are listed as priority habitats under the UK Biodiversity Action Plans, and over the last few years, management at Ainsdale has concentrated on restoring much of the dune system previously lost to commercial pine plantation. As well as the moss, this habitat restoration will benefit many other specialist species, including the natterjack toad and northern dune tiger beetle.


Long-leaved thread moss range

This species has a very scattered distribution in the UK. It has been recorded from Gwynedd, Merseyside, North Yorkshire, Caithness and Angus, although it is believed to have become extinct in its Welsh, Yorkshire and Angus sites. It still occurs in Ireland, and was last seen in 2001. Elsewhere, it is found in north-west and central Europe, Iceland, Siberia and the Altai region of Russia, North America and Greenland.

You can view distribution information for this species at the National Biodiversity Network Atlas.

Long-leaved thread moss habitat

Long-leaved thread moss is found in fens, wet calcareous soil, dune slacks and lake margins. In the UK, most records are from dune slacks.


Long-leaved thread moss status

Long-leaved thread moss is classified as Endangered in the UK, and protected under Schedule 8 of the Wildlife and Countryside Act 1981 as amended.


Long-leaved thread moss threats

The long-leaved thread moss is at risk from the lowering of the water table, and the subsequent drying out of the dunes slacks where it lives. The slacks have also been subjected to inundation by windblown sand, which also renders them unsuitable for the moss. Ainsdale NNR is also subject to a high level of public pressure, through visitors making recreational use of the extensive dunes and neighbouring beach.


Long-leaved thread moss conservation

Long-leaved thread moss is listed in the UK Biodiversity Action Plan, and included in English Nature's Species Recovery Programme. As with many bryophytes, collecting the information required to draw up an action plan for individual species can be difficult. Problems of accurate identification mean that past records cannot always be trusted and the true status of the plant hard to establish. Bryologists are being encouraged to look out for this and other uncommon species of moss in order to learn more about the habitat and climate requirements of this species. Once a better knowledge is gained, we will have a much better idea of just how threatened these mosses are, and how we might conserve them for the future.

The UK Biodiversity Action Plan for this species is available at UK BAP.
There may be further information about this species available via the National Biodiversity Network Atlas.

Find out more

For more information on threatened mosses and liverworts in Britain, see:



This information is awaiting authentication by a species expert, and will be updated as soon as possible. If you are able to help please contact:



Containing free calcium carbonate, chalky.
Dune slacks
Depressions between sand dunes that are often wet during the winter.



Image credit

Long-leaved thread moss  
Long-leaved thread moss

© British Bryological Society / National Museum & Gallery, Cardiff

National Museum & Gallery, Cardiff
Cathays Park
CF10 3NP
United Kingdom


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