''Cuphophyllus atlanticus'' is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

agaric An agaric () is a type of fungal fruiting body characterized by the presence of a pileus (cap) that is clearly differentiated from the stipe (stalk), with lamellae (gills) on the underside of the pileus. It is a type of mushroom (or toadstool) ...

(gilled mushroom) in the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Hygrophoraceae The Hygrophoraceae are a family (biology), family of fungi in the order (biology), order Agaricales. Originally conceived as containing white-spored, thick-gilled agarics (gilled mushrooms), including ''Hygrophorus'' and ''Hygrocybe'' species (th ...

. Until recently (2021), the species was considered to be conspecific with the North American '' Cuphophyllus canescens'', but DNA sequencing has shown that it is distinct. As ''C. canescens'', it has been given the recommended English name of felted waxcap in the United Kingdom. ''Cuphophyllus atlanticus'' has a European and North American distribution, occurring in Europe mainly in agriculturally unimproved grassland. Threats to its habitat have resulted in ''C. canescens'' (including ''C. atlanticus'') being assessed as globally "vulnerable" on the IUCN Red List of Threatened Species.

Taxonomy

The species was first described from Norway in 2021 as a result of

molecular A molecule is a group of two or more atoms that are held together by attractive forces known as chemical bonds; depending on context, the term may or may not include ions that satisfy this criterion. In quantum physics, organic chemistry, ...

research, based on

cladistic Cladistics ( ; from Ancient Greek 'branch') is an approach to biological classification in which organisms are categorized in groups ("clades") based on hypotheses of most recent common ancestry. The evidence for hypothesized relationships is ...

analysis of

DNA sequences A nucleic acid sequence is a succession of bases within the nucleotides forming alleles within a DNA (using GACT) or RNA (GACU) molecule. This succession is denoted by a series of a set of five different letters that indicate the order of the ...

. Previously, European specimens had been referred to the similar '' Cuphophyllus canescens'', but the latter species appears to be confined to North America.

Description

Basidiocarps In fungi, a basidiocarp, basidiome, or basidioma () is the sporocarp of a basidiomycete, the multicellular structure on which the spore-producing hymenium is borne. Basidiocarps are characteristic of the hymenomycetes; rusts and smuts do no ...

are

agaricoid An agaric () is a type of fungal fruiting body characterized by the presence of a pileus (cap) that is clearly differentiated from the stipe (stalk), with lamellae (gills) on the underside of the pileus. It is a type of mushroom (or toadstool), ...

, up to 40mm (1.5 in) tall, the cap broadly convex to flat when expanded, up to 40mm (1.5 in) across. The cap surface is smooth, dry, slightly felted, grey to bluish grey. The

lamellae Lamella (: lamellae) means a small plate or flake in Latin, and in English may refer to: Biology * Lamella (mycology), a papery rib beneath a mushroom cap * Lamella (botany) * Lamella (surface anatomy), a plate-like structure in an animal * Lame ...

(gills) are thick, decurrent (running down the stipe), pale grey. The stipe (stem) is smooth, white to pale grey, lacking a ring. The

spore print 300px, Making a spore print of the mushroom ''Volvariella volvacea'' shown in composite: (photo lower half) mushroom cap laid on white and dark paper; (photo upper half) cap removed after 24 hours showing warm orange ("tussock") color spore print. ...

is white, the spores (under a microscope) smooth,

inamyloid In mycology a tissue or feature is said to be amyloid if it has a positive amyloid reaction when subjected to a crude chemical test using iodine as an ingredient of either Melzer's reagent or Lugol's solution, producing a blue to blue-black staini ...

, subglobose, c. 5.5 to 6 by 4.5 to 5 μm.

Similar species

In Europe, the felted waxcap is distinguished from other grey species of '' Cuphophyllus'' by its dry, slightly felted cap that is never viscid or greasy. In North America, ''C. canescens'' is very similar, but is said to have drab or brownish tints in the cap and (microscopically) smaller, more globose spores measuring 4 to 5 μm across.

Distribution and habitat

In Europe, DNA studies have confirmed the presence of the felted waxcap in Norway, Sweden, and Scotland. This is the same northerly distribution previously noted for "''C. canescens''" in Europe. In North America, ''C. atlanticus'' has been confirmed from the United States (North Carolina) and Canada. Recent research suggests waxcaps are neither

mycorrhizal A mycorrhiza (; , mycorrhiza, or mycorrhizas) is a symbiotic association between a fungus and a plant. The term mycorrhiza refers to the role of the fungus in the plant's rhizosphere, the plant root system and its surroundings. Mycorrhizae play ...

nor

saprotrophic Saprotrophic nutrition or lysotrophic nutrition is a process of chemoheterotrophic extracellular digestion involved in the processing of decayed (dead or waste) organic matter. It occurs in saprotrophs, and is most often associated with fungi ...

but may be associated with mosses.

Conservation

In Europe, ''Cuphophyllus atlanticus'' is typical of

waxcap grassland Waxcap grassland is short-wikt:sward, sward, nutrient-poor grassland that supports a rich assemblage of larger fungi, particularly waxcaps (species of ''Hygrocybe'' and related genera), characteristic of such habitats. Waxcap grasslands occur pr ...

s, a declining habitat due to changing agricultural practices. As a result, the species is of global conservation concern and (as ''C. canescens''

sensu lato ''Sensu'' is a Latin word meaning "in the sense of". It is used in a number of fields including biology, geology, linguistics, semiotics, and law. Commonly it refers to how strictly or loosely an expression is used in describing any particular co ...

) is listed as "vulnerable" on the IUCN Red List of Threatened Species.

References