• Proposed
  • Under Assessment
  • Preliminary Assessed
  • LCAssessed
  • 5Published

Hygrophorus rainierensis Hesler & A.H. Sm.

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Scientific name
Hygrophorus rainierensis
Hesler & A.H. Sm.
Common names
IUCN Specialist Group
Mushroom, Bracket and Puffball
Assessment status
Preliminary Category
Proposed by
Noah Siegel
Noah Siegel
Anders Dahlberg

Assessment Notes


An uncommon fungus associated with conifers across northern USA and southern Canada. (Washington, Idaho, Michigan, USA. British Colombia and Nova Scotia, Canada.) If the western species can be shown to be a different species from eastern collections, this possibly could be revisited. Until such time, this should be listed as LC.

Taxonomic notes

This species belongs in the genus Cuphophyllus.

Why suggested for a Global Red List Assessment?

Geographic range

Distributed across northern USA and southern Canada. Originally described from Mt Rainier, Washington, USA.

Population and Trends

Appear to be a rare but widespread and scattered species in North America. Only 5 of the 20 records on Mycoportal (Feb 2018) are post 1970. Based on these records, it is difficult to conclude about its distribution, the size of the population and the whether the population is stable or not.  The wide and scattered distribution may imply it to be significantly overlooked.

Population Trend: Uncertain

Habitat and Ecology

The nutritional mode of Hygrophorus (Cuphophyllus) rainierensis is still not fully understood; it is presumably biotrophic, but how is not clear yet. Cuphophyllus (which H. rainierensiis belongs) are not saprotrophic, nor ectomycorrhizal (Griffith et al. 2002; Halbwachs et al. 2013; Seitzmann et al. 2011). Dispersal is by airborne spores. There is little knowledge about habitat preferences for H. rainierensis; forest type has not been mentioned with most collections, nor if it may occur in all forest ages, is confined to old growth forests or may re-establish after logging or clear cuts. A recent collection was in moss and grass, in an open area in old growth coniferous forest. One of 13 species named for Mt Rainier, which is now a protected island of old growth forest surrounded by clear-cuts, and forest managed as ‘tree farms’. There are very few modern collections of these species, and this one was used to highlight what is now considered a restricted and fragmented habitat.

Boreal ForestTemperate Forest


No threats have been identified. Research is needed to see if this species is restricted to old growth forests.

Conservation Actions

Research needed

Genetic studies are needed to see if the western North American species is the same as collections reported from eastern North America.

Habitat notes are needed; little is known about habitat preferences for this species. It may be restricted to old growth forests, or forests with limited disturbance.

Use and Trade

None known.


Griffith, G.W., G.L. Easton & A.W. Jones, 2002. Ecology and diversity of waxcap (Hygrocybe spp.) fungi. Botanical Journal of Scotland 54: 7–22.

Halbwachs H., P. Karsch & G.W. Griffith, 2013. The diversity of Hygrocybe – peeking into an enigmatic lifestyle. Mycosphere 4: 773–792. Doi 10.5943/mycosphere/4/4/14

Hesler, L.R. & A.H. Smith. 1963. North American Species of Hygrophorus. University of Tennessee Press, Knoxville.

Seitzman, B.H., Ouimette, A., Mixon, R.L., Hobbie, E.A., Hibbett, D.S. 2011. Conservation of biotrophy in Hygrophoraceae inferred from combined stable isotope and phylogenetic analyses. Mycologia 103: 280–290.

Country occurrence

Regional Population and Trends

Country Trend Redlisted