CRCritically Endangered

Larch Knight

Tricholoma psammopus

The Larch Knight (Tricholoma psammopus) is a distinctive mycorrhizal fungus that forms symbiotic relationships exclusively with larch trees. This medium-sized mushroom features a sandy-brown to grayish cap with a characteristic scaly surface and pale gills, typically fruiting in late autumn.

01Classification

Taxonomy & Classification

Kingdom

Fungi

Phylum

Basidiomycota

Class

Agaricomycetes

Order

Agaricales

Family

Tricholomataceae

Genus

Tricholoma

Larch Knight belongs to the family Tricholomataceae, order Agaricales, within the Agaricomycetes class.

02Description

Species Profile

The Larch Knight (Tricholoma psammopus) is a distinctive mycorrhizal fungus that forms symbiotic relationships exclusively with larch trees. This medium-sized mushroom features a sandy-brown to grayish cap with a characteristic scaly surface and pale gills, typically fruiting in late autumn. As a mycorrhizal partner, it plays a crucial role in nutrient exchange with larch forests, enhancing tree health and forest ecosystem stability.

The Larch Knight (Tricholoma psammopus) faces severe population decline primarily due to habitat loss from deforestation and land conversion in its limited range. Climate change poses additional pressure by altering the specific environmental conditions required for this mycorrhizal fungus to form associations with its host trees. The species' extremely restricted distribution makes it particularly vulnerable to local extinctions from human activities.

Key Facts

IUCN StatusCritically Endangered (CR)
GroupFungi
03Habitat

Habitat & Distribution

Larch Knight occurs in mature larch and mixed coniferous forests with well-drained, slightly alkaline soils rich in organic matter. The species shows strong preference for old-growth stands with established larch trees aged 40+ years, particularly in montane and subalpine zones where soil pH ranges between 6.5-7.5.

TERRESTRIALMajorTERRESTRIALMajor
04Threats

Threats

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IUCN Red List: Critically Endangered

The Larch Knight (Tricholoma psammopus) faces severe population decline primarily due to habitat loss from deforestation and land conversion in its limited range. Climate change poses additional pressure by altering the specific environmental conditions required for this mycorrhizal fungus to form associations with its host trees. The species' extremely restricted distribution makes it particularly vulnerable to local extinctions from human activities.

Climate change altering host tree relationships

HighOngoing

Habitat loss and deforestation

HighOngoing

Land use conversion for agriculture and development

HighOngoing

Limited geographic range increasing extinction risk

HighOngoing

Disruption of mycorrhizal networks

MediumOngoing
Community

Community Sightings

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07Sources

Sources & Attribution

How to Cite

IUCN: IUCN (2025). The IUCN Red List of Threatened Species. Version 2025-1. Available at: https://www.iucnredlist.org. doi:10.2305/IUCN.UK.2025-1.RLTS

GBIF: GBIF.org (2025). GBIF Home Page. Available at: https://www.gbif.org

This page: SpeciesRadar (2025). Larch Knight (Tricholoma psammopus). SpeciesRadar: Intelligence for Earth's Biodiversity. Available at: https://speciesradar.org/species/larch-knight

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