- Scientific name
- Catathelasma imperiale
- (Quél.) Singer
- Common names
- imperial mushroom
- náramkovec císařský
- náramkovka cisárska
- IUCN Specialist Group
- Mushroom, Bracket and Puffball
- Assessment status
- Assessment date
- IUCN Red List Category
- Krisai-Greilhuber, I.
- Mueller, G.M.
is a very large (up to 25 cm), showy and robust gilled mushroom with a double ring on the stipe. It is deeply inserted in soil with a root-like stipe base. It is an edible and searched for species with Holarctic distribution and is reported from East Asia, North America and Europe. It forms ectomycorrhizas with conifers, mainly in open montane Picea
forests. The forests have to be quite mature, well developed, not clear-cut and undisturbed. Soils are preferably calcareous. In the European Nordic countries there is considerable habitat loss of rich calcareous spruce forests as the calcareous areas often are small, already naturally fragmented, and situated in urbanized areas. The forest habitat, calcareous spruce forests is red-listed as Vulnerable in Norway, and these forests are regarded as declining in the same magnitude in Sweden. It is estimated that the mature/old-growth stands of rich/calcareous spruce forests have had a decline of >30% in Fennoscandia over 50 years (Brandrud 2015). Moist base-rich spruce and fir-spruce forests are endangered biotopes in Austria as well (Essl and Egger 2010). Catathelasma imperiale
is present worldwide with estimated 1800 localities and ]10800 mature individuals. Usually only a few mature individuals occur at each site. It is included in the Red Lists of 15 European countries and is considered declining everywhere due to eutrophication, habitat destruction and habitat change. The assessment is based on loss of obligate mycorrhizal hosts due to a decline in habitat area and quality.
It has a Holarctic distribution: E Asia (Japan, Korea), North America, Europe. In Europe its main distribution is boreal-subcontinental (Scandinavian Mountains, Limestone Alps). In Europe it is reported from the eastern (Russian Federation), southern (Italy), western (Eastern France, Belgium, Luxembourg), central (Switzerland, Liechtenstein, Austria, Germany, Slovakia, Poland), northeast (Estonia) and northern Europe (Finland, Norway, Sweden).
Population and Trends
The population is small and in parts of the distribution the area is declining, the area is fragmented due to clear cutting and fragmentation of older, high-productive spruce stands. In the European Nordic countries there is also considerable habitat loss of rich calcareous spruce forests as the calcareous areas often are small, already naturally fragmented, and situated in urbanized areas. The forest habitat, calcareous spruce forests is red-listed as Vulnerable in Norway, and these forests are regarded as declining at the same magnitude in Sweden. It is estimated that the mature/old-growth stands of rich/calcareous spruce forests have had a decline of >30% in Fennoscandia over 50 years (Brandrud 2015). Moist base-rich spruce and fir-spruce forests are endangered biotopes in Austria as well (Essl and Egger 2010). There is uncertainty about habitat trends outside of Europe.
Based on GBIF and databases available (see references) there are estimated 1800 localities worldwide. The number of mature individuals has been estimated at 10800 following recommendations in Dahlberg and Mueller (2011). The numbers of known localities is 900 and the number of yet unknown localities was estimated to be twice as high. Mature individuals are rare and rarely reach spore production state due to collecting activities.
This species is included on the Red List of the following countries: Austria (VU), Sweden (VU), Finland (NT), Estonia (regionally extinct), Slovakia (EN), Poland (EN/CR), Russian Federation (two regions). It is legally protected in Poland.
Population Trend: decreasing
Habitat and Ecology
It inhabits light montane coniferous forests, mainly Picea
forests, forest edges and limestone grassland with pines. The forests have to be quite mature, well developed, not clear-cut and undisturbed. Usually only a few mature individuals occur at each site. Its individuals are considered to be old and the reestablishment of individuals is very difficult after heavy forest cutting. It occurs on soils moderately dry to moist, neutral to alkaline, low in nitrogen but well supplied with bases, preferably calcareous mull and brown clay, terra fusca and base rich brown soils over limestone, calcareous marls and base rich silicates. It forms ectomycorrhizas with conifers.
In Europe it is mainly threatened by eutrophication, habitat loss and habitat quality changes. Details on habitat changes outside of Europe are sparse, but circumstantial data suggest that habitat in these countries is also in decline.
Conservation measures needed include reduction of eutrophication, especially pollution from nearby agricultural areas, and enhanced protection and management of known and suspected areas where the species occurs.
Research needed is investigation of distribution, population trends and ecological requirements of the species.
Use and Trade
It is a harvested as an edible for individual use.
Source and Citation
Krisai-Greilhuber, I. 2019. Catathelasma imperiale. The IUCN Red List of Threatened Species 2019: e.T147158431A147715294. https://dx.doi.org/10.2305/IUCN.UK.2019-2.RLTS.T147158431A147715294.en
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