Blue Tooth
Hydnellum caeruleum
Hydnellum caeruleum, commonly known as the blue-gray hydnellum, blue-green hydnellum, blue spine, blue tooth, or bluish tooth, is an inedible fungus found in North America, Europe, and temperate areas of Asia.
39
Countries
Photo: Wikimedia Commons (CC) via https://en.wikipedia.org/wiki/Hydnellum_caeruleum
Taxonomy & Classification
Kingdom
Fungi
Phylum
Basidiomycota
Class
Agaricomycetes
Order
Thelephorales
Family
Bankeraceae
Genus
Hydnellum
Blue Tooth belongs to the family Bankeraceae, order Thelephorales, within the Agaricomycetes class.
Species Profile
Hydnellum caeruleum, commonly known as the blue-gray hydnellum, blue-green hydnellum, blue spine, blue tooth, or bluish tooth, is an inedible fungus found in North America, Europe, and temperate areas of Asia.
Hydnellum caeruleum, the Blue Tooth fungus, faces severe decline primarily due to habitat loss from deforestation and agricultural conversion of old-growth forests where it forms essential mycorrhizal relationships. Air pollution, particularly nitrogen deposition, disrupts the delicate soil chemistry required for this species' survival. Climate change further threatens its specialized ecological niche by altering temperature and moisture conditions in its forest habitat.
Key Facts
Habitat & Distribution
Hydnellum caeruleum is mycorrhizal and often found in the humus beneath conifer trees. H. caeruleum is an ectomycorrhizal fungus native to temperate regions of Asia, Europe, and North America. The species is commonly found in pine and spruce ecosystems due to its mycorrhizal relationships with coniferous trees. A study on stipitate hydnoid fungi in Scottish coniferous forests, which focused on...
Threats
IUCN Red List: Critically Endangered
Hydnellum caeruleum, the Blue Tooth fungus, faces severe decline primarily due to habitat loss from deforestation and agricultural conversion of old-growth forests where it forms essential mycorrhizal relationships. Air pollution, particularly nitrogen deposition, disrupts the delicate soil chemistry required for this species' survival. Climate change further threatens its specialized ecological niche by altering temperature and moisture conditions in its forest habitat.
Agricultural conversion of forest ecosystems
Air pollution and nitrogen deposition
Disruption of mycorrhizal host tree relationships
Habitat loss and fragmentation from deforestation
Climate change altering forest conditions
Found in 39 Countries
Community Sightings
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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). Blue Tooth (Hydnellum caeruleum). SpeciesRadar: Intelligence for Earth's Biodiversity. Available at: https://speciesradar.org/species/blue-tooth