It is currently (2021) known from ca 300 locations (Mycoportal; Gbif.org), number of mature individuals is ca 3000. Estimated population size may be 3-fold higher, up to 9000 mature individuals. Estimated decline of populations due to continuing habitat loss or deterioration thanks to forestry policy during 3 generations (30 years) is >10%.

Misapplied: Leucopaxillus compactus (P. Karst.) Neuhoff
Synonym: Leucopaxillus pseudoacerbus (Costantin & L.M. Dufour) Boursier

Leucopaxillus tricolor is a large and fleshy saprotrophic fungus growing preferably on calcareous soil in deciduous forests (under Fagus, Quercus and Carpinus) with a long continuity. The taxon was originally described from the USA, and misinterpreted for decades as Leucopaxillus compactus in Europe. It is a widespread, but has small number of localities in the temperate and boreal (southern only) forests of Europe and North America. It is rare in the most of European countries, and red-listed over 10 countries.

General distribution holarctic, North America (Canada, USA), Europe, Asia (Turkey), Africa (Canary Islands).

The majority of localities is situated in Europe and North America (Canada, USA), few localities in Asia (Turkey) and Africa (Canary Islands). In Europe, Leucopaxillus tricolor occurs mostly in deciduous forests with Fagus, Quercus and Carpinus with a long continuity. Decrease has been noticed for the last 2-5 decades in some countries: France, Hungary, Lithuania, Slovenia based on Fraiture and Otto (2015).
Leucopaxillus tricolor is red-listed in Bulgaria, Czech Republic, Denmark, Estonia, Finland, France, Germany, Hungary, Lithuania, Norway, Poland (regional list), Spain and Sweden (Dahlberg and Croneborg 2006; Fraiture and Otto 2015). According to Dahlberg and Croneborg (2006) 34% of European localities is situated in protected or Natura 2000 areas.
In North America, where from the species was originally described, the majority of sites is located in north-east North America, also scattered reports in middle USA.
It is currently (2021) known from ca 300 locations (Mycoportal; Gbif.org), number of mature individuals is ca 3000. Estimated population size may be 3-fold higher, up to 9000 mature individuals. Estimated decline of populations due to continuing habitat loss or deterioration thanks to forestry policy during 3 generations (30 years) is >10%.

Leucopaxillus tricolor is a saprotrophic fungus growing in old-growth deciduous forests (Fagus, Quercus, Carpinus); it is considered at least mildly calciphilous.

The main threat is clear cutting and deterioration of habitats.

Conservation actions is needed in known sites.

There is no use and trade known.

Dahlberg A, Croneborg H. 2006. The 33 threatened fungi in Europe. Nature and envirnment, no. 136.

Kibby G, Henrici A, Spooner B. 2009. Leucopaxillus tricolor (Peck) Kühner new to Britain. Field Mycology 10(3): 86-89.

Fraiture A, Otto P. 2015. Distribution, ecology and status of 51 macromycetes in Europe. Results of the ECCF Mapping Programme. Scripta Botanica Belgica 53: 1-247.

Leucopaxillus compactus (Fr.) Neuhoff in GBIF Secretariat (2019). GBIF Backbone Taxonomy. Checklist dataset https://doi.org/10.15468/39omei accessed via GBIF.org on 2020-03-02.

Leucopaxillus tricolor (Peck) Kühner in GBIF Secretariat (2019). GBIF Backbone Taxonomy. Checklist dataset https://doi.org/10.15468/39omei accessed via GBIF.org on 2020-03-02.