It is currently (2021) known from ca 20 locations (Gbif.org) in Eurasia, number of mature individuals is ca 40. Estimated population size may be 10-fold higher, up to 400 mature individuals. Estimated decline of populations due to continuing habitat and substrate loss or deterioration thanks to forestry policy during 3 generations (30 years) is >20%; estimated number of mature individuals in each subpopulation is less than 50.
Preliminary assessment: EN C2a(i) VU D1.

Sequenced North American specimens belong into separate species (UNITE species hypotheses: https://unite.ut.ee/bl_forw_sh.php?sh_name=SH1511463.08FU#fndtn-panel1; https://unite.ut.ee/bl_forw_sh.php?sh_name=SH1511461.08FU#fndtn-panel1).
Thus, occurrence data from Canada and USA are excluded.

Chromosera cyanophylla is an omphalinoid waxcap with lilac-blue gills; saprotrophic on strongly decayed and moss-covered conifer trunks in virgin or natural forests with a long continuity. It has small number of localities in the temperate forests of Europe. Its habitat is in decline due to clearcutting.

Chromosera cyanophylla occurs in Europe (Austria, Czech, France, Germany, Italy, Norway, Slovakia, Spain, Sweden, Switzerland, Ukraine), but everywhere the taxon is extremely rare (1-5 localities per country). Few localities are known in Asia (China, Russian Far East).
Molecular study by Lodge et al. (2014) revealed significant differences between European and western North American collections, therefore most probably two separate species are present. Chromosera cyanophylla was originally described from Sweden, so under this name only Eurasian records are assessed. So far undescribed species occurs in North America (Canada, USA) and presumably also South America (Mexico).

It is currently (2021) known from ca 20 locations (Gbif.org) in Eurasia, number of mature individuals is ca 40. Estimated population size may be 10-fold higher, up to 400 mature individuals.

Develop estimation of individuals

Estimated decline of populations due to continuing habitat and substrate loss or deterioration thanks to forestry policy during 3 generations (30 years) is >20%; estimated number of mature individuals in each subpopulation is less than 50. Chromosera cyanophylla is red-listed in Czech (Holec & Beran 2006), Germany (Benkert et al.1992) and Norway (CR), and in the Red Data Book of Novosibirsk Oblast (2008) and Red Data Book of the Altai Republic (2007). Under protection in the Tigirek State Nature Reserve.

Chromosera cyanophylla is a wood-decomposing fungus growing on fallen logs of Norwegian spruce (Picea abies), silver fir (Abies alba), rarely Pinus cembra (decay stage 3-4) in virgin or natural forests. In Central Europe, Chromosera cyanophylla prefers montane old-growth forests (Fagus, Abies, Picea) that have been protected as nature reserves for a long time. In uplands country in Germany and Slovakia, most records are from forests located nearby large rivers. The species prefers stable humid microclimate under protective cover of trees.
Its status in Asia is poorly known. The basidiocarps are annual, but there have been observed both repeated or sporadic occurrence during several years.

The main threat is clear cutting or transforming of old-growth forests with high amount of coarse woody debris into managed forests with shorter rotation times and few or no coarse logs.

Conservation actions is needed in known sites. Retaining fallen spruce/ fir trunks in older commercial forests.

Taxonomical and molecular studies of North American and Asian materials of Chromosera species are needed.

There is no use and trade known.

Benkert et al.1992. ote Liste der gefährdeten Großpilze in Deutschland. – Deutsche Ges. Mykologie & Naturschutzbund Deutschland, Eching.

Chromosera cyanophylla (Fr.) Redhead, Ammirati & Norvell in GBIF Secretariat (2019). GBIF Backbone Taxonomy. Checklist dataset https://doi.org/10.15468/39omei accessed via GBIF.org on 2020-03-04.

Holec J, Beran M (eds) 2006. Červený seznam hub (makromycetů) České republiky [Red list of fungi (macromycetes) of the Czech Republic]. Příroda 24: 1–282.

Holec J, Kříž M, Beran M, Kolařík M. 2015. Chromosera cyanophylla (Basidiomycota, Agaricales) – a rare fungus of Central European old-growth forests and its habitat preferences in Europe. Nova Hedwigia 100(1-2): 189-204.

Læssøe T, Elborne SA. 2012. Chromosera Redhead, Ammirati & Norvell. In: Knudsen H, Vesterholt J (Eds.). Funga Nordica. Agaricoid, boletoid, clavarioid, cyphelloid and gastroid genera. 2nd edition. Nordsvamp, Copenhagen: 261.

Læssøe T, Petersen JH. 2019. Fungi of Temperate Europe 1. Princeton University Press.