• Proposed
  • Under Assessment
  • 3Preliminary Assessed
  • 4Assessed
  • 5Published

Geoglossum glabrum Pers.

Search for another Species...

Scientific name
Geoglossum glabrum
Common names
jazýček holý
pazoubek rašeliníkový
Schlanke Torfmoos-Erdzunge
Čūsku zemesmēlīte
Ziemiozorek gładki
IUCN Specialist Group
Cup-fungi, Truffles and Allies
Assessment status
Under Assessment
Proposed by
Viktor Kučera
Ivona Kautmanova, Viktor Kučera
Comments etc.
Irmgard Krisai-Greilhuber, Irja Saar, Inita Daniele, John Bjarne Jordal (old account), Izabela L. Kalucka, Tatyana Svetasheva, Anders Dahlberg

Assessment Notes


Geoglossum glabrum is a species of mires, bogs and wetlands. These habitats are declining mainly due to changing agricultural practices, development projects and pollution (airborne nitrogen deposition) and climate change. Over the distribution range we assume a total habitat and population decline of 15% over the past 50 years (approximately three generations). Habitat quality has also become impaired and the decline in population size over this time could be even higher. This decline in habitat is ongoing and expected to continue over the next 50 years. GBIF and national databases list 1 062 occurrences. Real number of localities might be up to more than 10 000, with 10 to 30 individuals at each and the species is assumed to have a population of more than 100 000 mature individuals. Though the populations is probably stable at a global scale the population decline is assumed to be on average >15% in 50 years (past, present and future) due to habitat decline. The species meets the threshold for NT (A2c+3c+4c).

Taxonomic notes

Geoglossum ophioglossoides (L.) Sacc.
Geoglossum sphagnophilum Ehrenb.

According to Jaklitsch & al. 2016 is better place this species into order Leotiales, Geoglossaceae

Jaklitsch W, Baral HO, Lucking R, Lumbsch HT, Frey W. 2016. Part 1/2 Ascomycota. In: W Frey (ed.). Syllabus of Plant Families: Adolf Engler’s Syllabus der Pflanzenfamilien.13th Edition. Borntraeger, Stuttgart. 322 p.

G. glabrum is often confused with Geoglossum simile which use to grow at similar localities. This misidentifications increase number of occurrences in some countries.

Why suggested for a Global Red List Assessment?

Rare species and is threatened by liquidation of wetland habitats

Geographic range

Geoglossum glabrum has boreal distribution and outside the boreal zone, on suitable habitats and refugials of boreal flora on raised peat bogs.
It seems it is missing in mediterranean area due to absence of suitable habitats.

Population and Trends

Geoglossum glabrum grows on very special old habitats. Without any disturbtion they can produce several fruitbodies every year. It seems the populations are stabile without strong spreading or decreasing tendency. They are not very numerous but fruitbodies occures routinely.

Population Trend: Stable

Habitat and Ecology

The active raised bogs (#7110 in Natura 2000) as typical biotope of Geoglossum glabrum are important habitats of boreal flora in central Europe. These are natural open plant communities of ombrotrophic bogs, which are mosaic and where are bog hummocks, ridges and lawns. The main ecological character is oligotrophic to dystrophic water with acidic reaction with low content of nutrition and bases. An important biotope! It herblayer is formed by numerous rare and endangered species eg. Oxycoccus palustris, Drosera rotundifolia, Eriophorum vaginatum…A well-developed layer of bryophytes is dominated by numerous species of the genus Sphagnum. Geoglossum glabrum is saprotroph growing in Sphagnum bogs. It is specific for peat bog habitats. In Nordic countries occure also in swampy forests and pastures (Ohenoja 2000). In central Europe the species is always associated with Sphagnum and often accompanied with Hygrocybe coccineocrenata and H. turunda. In Slovakia are active raised bogs very rare because of their south distribution range. 

Bogs, Marshes, Swamps, Fens, Peatlands [generally over 8 ha]


Endangered by destruction of habitats, climate changes and pollution. Impact of anthropogenic activity is at the first place, the decrease of groundwater level. That way succession on the locality is accelerated. Another indirect influence is the eutrophication of the environment associated with the intensification of agricultural and industrial production. Direct anthropic influences include the use of the peat bogs as a source of organic matter by mining and the conversion into meadows, fields or forests.

Scale Unknown/UnrecordedMining & quarryingUnintentional effects: large scale (species being assessed is not the target) [harvest]Unintentional effects: subsistence/small scale (species being assessed is not the target) [harvest]Other ecosystem modificationsDroughts

Conservation Actions

The only way how to protect Geoglossum glabrum is conservation of peat bogs habitat and preventing of the degradation of the sites of its actual and potential occurrence. At places where succession is strongly developping the appropriate management measure (controled mowing) is needed.

Site/area protectionResource & habitat protectionSite/area management

Research needed

Monitoring of currently known localities and target searching for next suitable habitats in western Europe and Carpathian Arc region.

Population size, distribution & trendsArea-based Management Plan

Use and Trade

The species is not known to be used.


Holec, J., Beran, M. (eds), 2006. Červený seznam hub (makromycetů) České republiky [Red list of fungi (macromycetes) of the Czech Republic]. Příroda, 24. Praha: Agentúra ochrany přirody a krajiny. 282 p.
Ohenoja E. 2000. Geoglossaceae Corda, pp. 177–183. In: Hansen, L. & Knudsen H. (eds), Nordic macromycetes 1. Nordsvamp, Copenhagen.
Nannfeldt J.A. 1942. The Geoglossaceae of Sweden (with regard also to the surrounding countries). Ark. Bot. 30: 1–67.
Mains E.B. 1954. North American species of Geoglossum and Trichoglossum. Mycologia 46: 586–631.
Durand E.J. 1908. The Geoglossaceae of North America. Ann. Mycol. 6: 387–477. 
Hustad V. P., Kučera V., Rybáriková N., Lizoň P., Gaisler J., Baroni T. J., Miller A. N. 2014. Geoglossum simile of North America and Europe: distribution of a widespread earth tongue species and designation of an epitype. Mycological Progress, 13 (2014), pp. 857-866
Fedosova A. G. Semeistvo Geoglossaceae (Ascomycota) v Rossii [Family Geoglossaceae (Ascomycota) in Russia]: PhD (Cand. of Biol.) thesis. St. Peterburg, 2019. 293 p. Федосова А. Г. Семейство Geoglossaceae (Ascomycota) в России: дис. канд. биол. наук. СПб., 2019. 293 с. [in Russian]

Country occurrence

Regional Population and Trends

Country Trend Redlisted