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Paraxerula caussei (Maire) R.H. Petersen

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Scientific name
Paraxerula caussei
(Maire) R.H. Petersen
Common names
Grauhaariger Wurzelrübling
slizečka černá
IUCN Specialist Group
Mushroom, Bracket and Puffball
Assessment status
Assessment date
IUCN Red List Category
IUCN Red List Criteria
Krisai-Greilhuber, I.
Mueller, G.M.

Assessment Notes

The content on this page is fetched from The IUCN Red List of Threatened Species: https://www.iucnredlist.org/species/147537697/148154512


Paraxerula caussei is a medium sized thinfleshed gilled mushroom with a tomentose blackish grey cap and a long radicant stipe. It is a meso-thermophilic saprotrophic species growing on dead Fagus-roots, mainly in climax beech forest over limestone. It is a European species present from the submediterranean to the temperate zone and recorded from throughout Europe except for northern areas. It is included in Red Lists of nine countries. Based on GBIF and databases available (see references) 234 localities are estimated worldwide. The number of mature individuals has been estimated at 1400 with a number of mature individuals in each subpopulation of less than 250. The habitat types Mullbraunerde-beech forest, mesophil limestone beech forest, and thermophile limestone beech forest are endangered biotope types in Austria (Essl and Egger 2010).

The species is assessed as VU C2a(i) based on its quite small population size, fragmentation, loss of habitat and a diminishing habitat quality.

Taxonomic notes

Paraxerula is the current name (Petersen and Hughes 2010).

Geographic range

This is a European species distributed in the submediterranean to temperate zones, recorded from South and South-East, West-, Central and southern North Europe.

Population and Trends

Mature individuals are  rare.  Based on GBIF and databases available (see references) there are 234 estimated localities worldwide. The number of mature individuals has been estimated at 1400 following Dahlberg and Mueller (2010). Localities are widely dispersed and not strongly fragmented.

Population Trend: decreasing

Habitat and Ecology

It is a meso-thermophilic saprotroph growing on dead Fagus-roots in calcareous beech forests. It is primarily restricted to climax beech forest over limestone with shallow base-saturated clay soil, or on immature “Kalkbraunerde” or Malmlimestone.


It is endangered by fertilizer input, surface acidification, biotope destruction (logging) and biotope alteration (conversion of beech forests into coniferous and other forests) and land use development, e.g., for recreation.

Conservation Actions

Reduction of fertilizer inflow via water and air from adjacent agriculture is needed, as is habitat protection.  Halting conversion of Fagus dominated forests into conifer plantations. 

Further investigation of population size, population trends and habitat requirements is needed. 

Source and Citation

Krisai-Greilhuber, I. 2019. Paraxerula caussei. The IUCN Red List of Threatened Species 2019: e.T147537697A148154512. https://dx.doi.org/10.2305/IUCN.UK.2019-2.RLTS.T147537697A148154512.en .Accessed on 3 February 2024

Country occurrence