Assessment Notes

Justification

Odontiochaete alba is only known from its description in 1940 from Brazil. There are no more records or information available on this species, so it is assessed as Data Deficient (DD).

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Taxonomic notes

This is the type species in the monotypic genus Odontiochaete, established in 1940 based on its morphological characteristics (Rick 1940).

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Geographic range

Odontiochaete alba was described in 1940 based on a single collection from southern Brazil (Santa Maria state). Its type locality is in a transition zone between the Pampa and the southern Brazilian Atlantic Forest, characterized currently as a developed and urbanized region.

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Population and Trends

Odontiochaete alba is the only species within its genus, known only from one site in a transition zone between the Pampa and the southern Brazilian Atlantic forest. The species was described more than 80 years ago, and never found again. Any reliable population size inference is currently hindered by lack of data, as the species is known only from its original publication. 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

Its specific habitat requirements (both biotic and abiotic), ecology, and distribution throughout the Pampa and the Brazilian Atlantic Forest are unknown, but this species was found growing on rotting wood (Rick 1940).

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Threats

Odontiochaete alba was described based on a collection in a transition zone between the southern Brazilian Atlantic Forest and the Pampa, where it is reasonable to assume that the species is potentially distributed. 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 more research into the distribution, population size and ecology for this species 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. Odontiochaete alba. The IUCN Red List of Threatened Species 2025: e.T265979485A266019723. Accessed on 23 November 2025.

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• Country occurrence