Collybia

''Collybia'' (in the strict sense) is a genus of mushrooms in the family Clitocybaceae. The genus has a widespread distribution in northern temperate areas, and contains well known species like the Collybia nuda, blewit, Collybia sordida, sordid blewit, and Collybia phyllophila, frosty funnel, as well as various species that grow on the decomposing remains of other mushrooms. The name ''Collybia'' means "small coin".

History of taxonomy

Until recently a large number of other white-spored species, some very common, were assigned to this genus, but the majority have been separated into other genera: ''Gymnopus'', ''Rhodocollybia'' and ''Dendrocollybia'', leaving the genus with only three species. Later, research published in 2023 reassigned a number of species previously considered to be in the genus ''Clitocybe'' to the genus ''Collybia'', including the edible blewit and brownit mushrooms, expanding the genus once again.

''Collybia'' sensu lato (1820s to 1990s)

''Collybia'' sensu lato is one of the groups of fungi of the order Agaricales that has created Taxonomy (biology), taxonomic differences of opinion in the scientific community. The generic name ''Collybia'' is due to Elias Magnus Fries and first appeared in 1821. ''Collybia'' was originally a tribe (biology), tribe from an Agaricus classification. In 1857, Friedrich Staude recognized ''Collybia'' as a genus. Later in his systematic work of 1838, Fries characterized ''Collybia'' as those species with:
#white spores,
#incurved cap margin,
#central cartilaginous stipe, and
#fruit bodies which decay easily ("putrescent").
The last criterion divided these mushrooms from those of ''Marasmius'', which had the property of being able to revive after having dried out (called "marcescent"). Although Fries considered this an important characteristic, some later authors like Charles Horton Peck (1897) and Calvin Henry Kauffman (1918) did not agree with Fries's criteria for the classification, and Gilliam (1976) discarded marcescence as a characteristic for the identification and differentiation of these genera.

At that point, the very varied genus encompassed the modern genera ''Oudemansiella'' (including ''Xerula''), ''Crinipellis'', ''Flammulina'', ''Calocybe'', ''Lyophyllum'', ''Tephrocybe'', ''Strobilurus (fungus), Strobilurus'', and others.

''Collybia'' sensu stricto (1990s to 2023)

In 1993, Vladimír Antonín and Machiel Noordeloos published the first part of a monograph of the genera ''Marasmius'' and ''Collybia'' after conducting a survey of these genera in Europe. In 1997, they published the second part of the monograph that included all ''Collybia'' species. In 1997, Antonín and colleagues published a generic concept within these two genera and organized the nomenclature to provide a new combination of genera: ''Gymnopus'', ''Collybia'', ''Dendrocollybia'', ''Rhodocollybia'' and ''Marasmiellus''.

The nomenclature and reclassification has since been supported by subsequent molecular phylogenetics, molecular analysis. Most of these mushrooms belong to the family Marasmiaceae and have low convex caps and white gills, with Lamella (mycology), adnate attachment to the stem. This general form has given rise to the term ''collybioid'', which is still in use to describe this type of fruit body.

The type species for ''Collybia'' sensu stricto is ''C. tuberosa'', a small white parasitism, parasitic mushroom (with caps up to ) which develops from a reddish-brown apple seed-shaped sclerotium in and on putrescent fungi or remaining in soil after complete decay of the host tissue.

The three species remaining in the genus (''Collybia cirrhata, C. cirrhata, Collybia cookei, C. cookei'', and ''Collybia tuberosa, C. tuberosa'') are small, up to . The caps are whitish and often radially wrinkled. All three species are saprobic, and grow on the decomposing remains of other mushrooms. When the genus was split up, the much-reduced genus was moved from ''Marasmiaceae'' to ''Tricholomataceae''.

Expansion of ''Collybia'' in 2023

In 2023, Zheng-Mi He ''et al''. published a molecular phylogenetics and phylogenomics study exploring the phylogenetic relationships and evolutionary history of the family Clitocybaceae, resulting in a large scale expansion of the genus ''Collybia'' to include many species previously classified as ''Clitocybe''. He and colleagues also divided the genus into 4 subgenera: ''Collybia'' (containing, among others, the three original species of ''Collybia'' sensu stricto), ''Leucocalocybe'' (containing the well known blewits), ''Crassicybe'', and ''Macrosporocybe''. The genus now includes these species:

* subgenus ''Collybia''
** ''Collybia alboclitocyboides''
** ''Collybia aperta''
** ''Collybia asiatica''
** ''Collybia bisterigmata''
** ''Collybia brunneoumbilicata''
** ''Collybia cirrhata ―'' piggyback shanklet
** ''Collybia cookei'' ''―'' split-pea shanklet
** ''Collybia dealbata''
** ''Collybia dryadicola''
** ''Collybia humida''
** ''Collybia hunanensis''
** ''Clitocybe odora, Collybia odora'' ― aniseed funnel
** ''Collybia pannosa''
** ''Collybia petaloidea''
** ''Collybia phyllophila'' ― frosty funnel
** ''Collybia piceata''
** ''Collybia rivulosa''
** ''Collybia subtropica''
** ''Collybia tibetica''
** ''Collybia tomentostipes''
** ''Collybia tuberosa'' ― lentil shanklet
** ''Collybia xylogena''
* subgenus ''Crassicybe''
** ''Collybia irina''
* subgenus ''Leucocalocybe''
** ''Collybia brunneocephala ―'' brown blewit
** ''Collybia fibrosissima''
** ''Collybia mongolica''
** ''Collybia nuda'' ― blewit
** ''Collybia personata'' ― field blewit
** ''Collybia sordida'' ― sordid blewit
* subgenus ''Macrosporocybe''
** ''Collybia striaticeps''

See also

*List of Tricholomataceae genera
*List of Marasmiaceae genera

References

{{Authority control

Tricholomataceae
Agaricales genera

de:Rüblinge
Taxa described in 1821