Assessment Notes

Justification

Gloeoasterostroma sordidum was described in 1938 from Brazil, and there have only been two known collecting sites. No additional records or information are available, so the species is assessed as Data Deficient (DD).

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Taxonomic notes

This is the only species in the monotypic genus Gloeoasterostroma, established in 1938. However, the genus' legitimacy has been questioned (Donk 1964).

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Geographic range

Gloeoasterostroma sordidum was described in 1938 based on a single collection from southern Brazil (Santa Maria state), within a transition zone between the Pampa and the Brazilian Atlantic Forest. There is also a single collection from northeastern Brazil (Bahia state), within the Brazilian Atlantic Forest.

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Population and Trends

Gloeoasterostroma sordidum is the only species within its genus, known only from two sites within the northeastern Brazilian Atlantic forest and a transition zone between the Pampa and the southern Brazilian Atlantic forest. Any reliable population size inference is currently hindered by a lack of data. Nevertheless, the southern Brazilian Atlantic Forest has decades of sampling efforts from several mycologists, indicating that the species might be rare throughout its potential habitat. Additionally, the Brazilian Atlantic Forest is severely fragmented, being now reduced to only 28% of its original size, and being mainly composed by secondary fragments (Rezende et al. 2018), indicating that the species unknown population is threatened by habitat area and quality loss. The Pampa is also threatened by land use changes, mainly due to extensive agriculture.

Population Trend: Unknown

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Habitat and Ecology

Gloeoasterostroma sordida was recorded as growing on bark. Its specific habitat requirements (both biotic and abiotic), ecology, and distribution throughout the Pampa and the Brazilian Atlantic Forest are unknown.

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Threats

The Brazilian Atlantic Forest is considered a biodiversity hotspot, being severely fragmented and reduced to only 28% of its original area (Rezende et al. 2018), suffering pressures due to urban expansion, deforestation, and agriculture. Also, the Pampa has been suffering in recent years pressures related with land-use change, mainly triggered by extensive agriculture. The scale of the impact of such threats on this species, however, are unknown.

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Conservation Actions

Specific conservation actions designed to protect the species population are currently hindered due to lack of understanding of its distribution and population size. A taxonomic review and further research into its distribution, population size and habitat preferences are needed.

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Use and Trade

No use/trade is known.

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Source and Citation

Cunha, S.P. & Gonçalves, S.C. 2025. Gloeoasterostroma sordidum. The IUCN Red List of Threatened Species 2025: e.T265979959A266021281. Accessed on 27 November 2025.

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• Country occurrence