Assessment Notes

Justification

This wood-inhabiting poroid fungus forms resupinate or slightly reflexed basidiomata on small dead branches of shrubs and on stems of some woody herbs. It was originally discovered in Prunus-dominated, UK coastal scrub habitats with strong Atlantic influence. First recorded in 2004, and originally described in 2008, it has a worldwide distribution that still shows a stronghold in those parts of Britain exposed to the strongest Atlantic climatic influence (the extreme SW and near the S coast of England and on the island of Anglesey in north Wales). There is also one collection from the Channel Isles (Guernsey) and three records documented from Asturias, northern Spain. This species is suspected to be present along the Atlantic coast of northern France (and perhaps also of Ireland and Portugal), nevertheless the global range is still expected to be very restricted. Around 200 mature individuals are known from Britain, Guernsey and Spain. The total number of mature individuals could be 10 times greater than currently known and if the species is shown to be present elsewhere in west Europe, then the total could be 40 times greater. No current threats to habitat and no other evidence of decline. It is assessed as Least Concern (LC).

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Taxonomic notes

Now recombined as Polyporus efibulatus (A.M. Ainsw. & Ryvarden) Melo & Ryvarden, Syn. Fung. (Oslo) 37: 353 (2017)

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Geographic range

Recorded in 176 localities (= fruiting individuals) in England & Wales exposed to the strongest Atlantic climatic influence, one locality in Guernsey (Channel Islands) and three in northern Spain. 94% of these localities were recorded by one person (Ken Preston-Mafham) in Cornwall. This species favours sites with a strong Atlantic influence and it is also expected to occur in Ireland, northerrn France and Portugal although very few people are searching for resupinate polypores. The global range is expected to be very restricted.

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Population and Trends

From observations of inhabited deadwood and the mycelial territories delimited therein, this species seems to be present as a single mature individual per fruiting patch. Such patches are relatively short (usually <15 cm) and so fruiting patches can be taken as representing mature individuals. Around 200 mature individuals are known from Britain, Guernsey and Spain. This species favours sites with a strong Atlantic influence and it is also expected to occur in Ireland, northern France and possibly Portugal although very few people are searching for resupinate polypores. The total number of British mature individuals could be 10 times greater than currently known and if the species is shown to be present elsewhere in western Europe, then the total could be 40 times greater. There are no current threats to habitat and no other evidence of decline.

Population Trend: stable

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Habitat and Ecology

It is a white-rot saprotroph of small diameter dead branches (usually attached) of various shrubs and stems of some woody herbs, perhaps most frequently found in Atlantic coastal thickets of Corylus and Rosaceae (Prunus spinosa, Rosa, Rubus) and widespread across Cornwall. It has been recorded on Acer, Carpinus, Chamerion, Corylus, Crataegus, Fagus, Forsythia, Fraxinus, Hedera, Ilex, Malus, Pinus, Prunus, Quercus, Rosa, Rubus, Salix, Ulex and Vitis. Around the UK coastal localities, the fungus favours Prunus-dominated scrub habitat such as occurs along the long-distance coastal footpaths, but elsewhere it seems to occur on dead, usually attached, twigs of many woody plants.

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Threats

There are no major threats to this species in the short term.

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Source and Citation

Ainsworth, A.M. 2022. Polyporus efibulatus. The IUCN Red List of Threatened Species 2022: e.T126002848A218988944. https://dx.doi.org/10.2305/IUCN.UK.2022-2.RLTS.T126002848A218988944.en .Accessed on 3 February 2024

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• Country occurrence