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Sarcosoma globosum (Schmidel) Casp.

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Scientific name
Sarcosoma globosum
(Schmidel) Casp.
Common names
witches cauldron
саркосома шаровидная
mäsovec guľatý
Toverīšu sarkosoma
Paprastasis taukius
masečník kulovitý
Gallertkugel, Kugeliger Gallertbecherling
IUCN Specialist Group
Cup-fungi, Truffles and Allies
Assessment status
Assessment date
IUCN Red List Category
Dahlberg, A.
Minter, D.

Assessment Notes

The content on this page is fetched from The IUCN Red List of Threatened Species: https://www.iucnredlist.org/species/58515314/58515381


Sarcosoma globosum is a well known, conspicuous and much studied fungus with its main distribution in northern Europe. It has decreased throughout its range, and disappeared from many parts of Europe. The prime cause for decline is changing land management, above all the practice of clear cutting old-growth forests. This causes the species to disappear. The practice of allowing cattle to graze in forests, which was beneficial for this fungus, has largely ceased, and that is also having a negative impact. The fungus is nationally red-listed in 10 European countries, and is thought to be extinct in several central European countries. The status of the species in Russia is a little unclear. The status and trend of the population is inferred from field observations combined with the known habitat decline. Past, ongoing and future habitat declines are estimated to impact negatively on all populations of S. globosum, and the future looks bleak for this species. Estimated decline of area and quality of appropriate forest habitat has been and will continue to be be just under 30 % over 50 years. The length of evaluation period used for these estimates (50 years = three generations) follows recommendations of Dahlberg and Mueller (2011). Only criterion A applies as the species is widely distributed and the estimated total population size disqualifies use of criteria B-D. It is listed as Near Threatened because it almost qualifies for listing as Vulnerable under criteria A2c+3c+4c . 

Geographic range

Sarcosoma globosum is a circumpolar boreal and hemiboreal species with its main distribution in northern Europe (Dahlberg and Croneborg 2003, Nitare 2009). The most dense distribution occurs in southeastern and, to a lesser degree, northeastern, Sweden. It is also well distributed in Finland and certain areas in Russia, although less well documented, may also be important. The few occurrences in central Europe represent small, fragmented subpopulations close to the edge of its natural range. It occurs rarely in eastern parts of North America, but those records may also include similar but different, misidentified species. It is not known from western North America.

Population and Trends

Globally, the main stronghold of Sarcosoma globosum is Sweden, where it is well known and has been much looked after since the early twentieth century (Nitare 2009). There have been more than 2,000 reports from 150 known localities, with an estimate of 300 localities in total and a suspected population of 6,000 mature individuals in Sweden (ArtDatabanken 2015). It is rare in Finland, with 80 reported observations since 1915 (Ohenoja, Kaukonen and Routsalainen 2013 ). Information about its occurrence in Russia is incomplete, but it has been reported from many regions and may be locally common. It is rare outside Sweden, Finland and Russia. It has become nationally extinct in some European countries and is reported to decline throughout its range. A Species Action Programme for Sarcosoma globosum 2010-2014 in Sweden provided a compilation of the species biology, status in Sweden and Europe as well suggestions of needed actions for conservation (Nitare 2009). The programme (in Swedish, with an English summary) can be downloaded.

Population Trend: decreasing

Habitat and Ecology

Sarcosoma globosum is commonly considered to be a litter-decomposing terrestrial fungus. Its life-form, however, is not known and it is still unclear whether it is saprotrophic or mycorrhizal. It grows on nutrient-rich and well drained soils, in older mossy stands dominated by Picea (spruce) and with a long history of continuous use as forest. Carpophores are produced shortly after snow melt in early spring. The mycelium is thought to be long-lived, perhaps up to several decades. In southern and central Sweden it often occurs next to eskers or outwash of moraine ridges in forests that have usually been grazed by cattle for several hundred years, but the practice of forest grazing by cattle was abandoned in the middle of the twentieth century. These forests have usually been subject to extensive selective tree felling but have never been clear-cut. The typical habitat in northern Sweden, Finland and Russia, is aged spruce forests along rivers and brooks, often on alluvial shores. The localities are typically nutrient-rich habitats directly adjacent to watercourses, e.g. in ravines, old waterway banks and other coarse and fine sandy sediment habitats.


The main threat is decline and degradation of habitat through logging. In Sweden, the post-1950 abandonment of forest cattle grazing (which was beneficial for this fungus) has also been significant. The fungus disappears after clear-cutting and seems not to re-colonize the managed forests which replace the original habitat. There are no reports of the fungus in plantations. Most of the appropriate spruce forests in northern Europe, >90%, are managed with a forest rotation-time of 70-100 years. The clear-cutting at the end of that period reduces the potential habitat, and decline is expected to continue at a rate of about 1%/year. Most populations located in sites outside protected areas are expected to disappear in the future. The ending of forest cattle grazing has resulted in more dense forest habitats which are unsuitable for this fungus.

Conservation Actions

This species was short-listed by the European Council for Conservation of Fungi for inclusion in Appendix I of the the Bern Convention (Dahlberg and Cronestam 2001). It is nationally red-listed or classified as rare in 12 European countries and regions (Armenia CR; Czech Republic RE; Finland NT; Germany RE;  Latvia CR; Lithuania RE; Norway CR; Poland EN; Russia (Leningrad region) 2; Slovakia RE;  Sweden VU; Ukraine rare). It can survive extensive selective logging, but not clear-cutting. Important  localities should be protected and managed, for example by careful thinning when needed in a long-term to perspective to prevent overgrowth. A Species Action plan for Sarcosoma globosum (2010-2014) was undertaken in Sweden by the Swedish Environmental Protection Agency (Nitare 2009, downloadable from www.naturvardsverket.se).

Use and Trade

The species is not used.

Source and Citation

Dahlberg, A. 2015. Sarcosoma globosum. The IUCN Red List of Threatened Species 2015: e.T58515314A58515381. https://dx.doi.org/10.2305/IUCN.UK.2015-4.RLTS.T58515314A58515381.en .Accessed on 1 February 2024

Country occurrence