''Pholiotina'' is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

of small

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) ...

fungi. It was circumscribed by Swiss mycologist

Victor Fayod Victor Fayod (23 November 1860 – 28 April 1900) was a Swiss mycology, mycologist who created an influential novel classification of the agaric Fungus, fungi and described a number of new genera and species. Biographical overview Fayod was b ...

in 1889 for '' Conocybe''-like species with

partial veil In mycology, a partial veil (also called an inner veil, to differentiate it from the "outer", or universal veil) is a temporary structure of tissue found on the fruiting bodies of some Basidiomycota, basidiomycete fungus, fungi, typically agarics. ...

s. The genus has since been expanded to include species lacking partial veils.

Taxonomic details

The genus ''Pholiotina'' is defined as small thin ''

Mycena ''Mycena'' is a genus of about 500 species of fungi. Rarely more than a few centimeters in width, the mushrooms are characterized by a small conical or bell-shaped cap and a thin fragile stem. Most are grey or brown, but a few species have brigh ...

''-like

mushroom A mushroom or toadstool is the fleshy, spore-bearing Sporocarp (fungi), fruiting body of a fungus, typically produced above ground on soil or another food source. ''Toadstool'' generally refers to a poisonous mushroom. The standard for the n ...

s, with an hymenoderm

pileipellis The pileipellis is the uppermost layer of hyphae in the pileus of a fungal fruit body. It covers the trama, the fleshy tissue of the fruit body. The pileipellis is more or less synonymous with the cuticle, but the cuticle generally describes ...

, a dry

cap A cap is a flat headgear, usually with a visor. Caps have crowns that fit very close to the head. They made their first appearance as early as 3200 BC. The origin of the word "cap" comes from the Old French word "chapeau" which means "head co ...

surface,

cystidia A cystidium (: cystidia) is a relatively large cell found on the sporocarp of a basidiomycete (for example, on the surface of a mushroom gill), often between clusters of basidia. Since cystidia have highly varied and distinct shapes that are o ...

that are sub-capitate to blunt, and spores which are rusty brown in deposit.

Spore In biology, a spore is a unit of sexual reproduction, sexual (in fungi) or asexual reproduction that may be adapted for biological dispersal, dispersal and for survival, often for extended periods of time, in unfavourable conditions. Spores fo ...

s of mushrooms of this genus are thick walled, smooth and have a

germ pore A germ pore is a small pore in the outer wall of a fungal spore through which the germ tube exits upon germination. It can be wikt:apical, apical or eccentric in its location, and, on light microscopy, may be visualized as a lighter coloured are ...

. Victor Fayod designated ''Pholiotina blattaria'' as the

type species In International_Code_of_Zoological_Nomenclature, zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the spe ...

of ''Pholiotina'', but this name was used for many different species of ''Pholiotina'' with partial veils and it is unclear which species is really ''P. blattaria'', which makes it a

nomen dubium In binomial nomenclature, a ''nomen dubium'' (Latin for "doubtful name", plural ''nomina dubia'') is a scientific name that is of unknown or doubtful application. Zoology In case of a ''nomen dubium,'' it may be impossible to determine whether a ...

. He designated a

lectotype In biology, a type is a particular specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally associated. In other words, a type is an example that serves to anchor or centralizes ...

for this species in the same publication, and microscopic examination revealed that this specimen belongs to the species ''P. vexans'', making ''P. vexans'' the current type species of ''Pholiotina''. Some authors considered ''Pholiotina'' part of the genus '' Conocybe''. However, a

molecular phylogenetics Molecular phylogenetics () is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to ...

study has shown that, while ''Pholiotina'' as currently defined is

polyphyletic A polyphyletic group is an assemblage that includes organisms with mixed evolutionary origin but does not include their most recent common ancestor. The term is often applied to groups that share similar features known as Homoplasy, homoplasies ...

, the three

clades In biology, a clade (), also known as a monophyletic group or natural group, is a group of organisms that is composed of a common ancestor and all of its descendants. Clades are the fundamental unit of cladistics, a modern approach to taxonomy ...

that have been placed in ''Pholiotina'' are more closely related to other genera than to ''Conocybe''. The two genera can be distinguished microscopically: ''Pholiotina'' contains a differentiated central zone called a mediostratum that is lacking in ''Conocybe''. Additionally, most ''Pholiotina'' species have

with rounded to tapered tips, compared to the enlarged, globular cystidial tips of ''Conocybe''. In a 2007 publication, Hausknecht and Krisai-Greilhuber devised an infrageneric

classification Classification is the activity of assigning objects to some pre-existing classes or categories. This is distinct from the task of establishing the classes themselves (for example through cluster analysis). Examples include diagnostic tests, identif ...

that includes the

sections Section, Sectioning, or Sectioned may refer to: Arts, entertainment and media * Section (music), a complete, but not independent, musical idea * Section (typography), a subdivision, especially of a chapter, in books and documents ** Section sig ...

''Piliferae'' and ''Vestitae'', and the

series Series may refer to: People with the name * Caroline Series (born 1951), English mathematician, daughter of George Series * George Series (1920–1995), English physicist Arts, entertainment, and media Music * Series, the ordered sets used i ...

''Aeruginosa'', ''Aporos'', ''Appendiculata'', ''Brunnea'', ''Coprophila'', ''Filipes'', ''Keniensis'', ''Mairei'', ''Pygmaeoaffinis'', ''Resinosocystidiata'', ''Sulcata'', ''Teneroides'', ''Utriformis'', and ''Vexans''. However, a 2013 study by Tóth '' et al.'' found ''Pholiotina'' as it is currently defined to be

, with one

clade In biology, a clade (), also known as a Monophyly, monophyletic group or natural group, is a group of organisms that is composed of a common ancestor and all of its descendants. Clades are the fundamental unit of cladistics, a modern approach t ...

forming the

sister group In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree. Definition The expression is most easily illustrated by a cladogram: Taxon A and ...

to '' Descolea'', another forming the sister group to '' Bolbitius'' and another forming the sister group to '' Galerella nigeriensis''. All the species of ''Pholiotina'' with partial veils and some species without, including the type species, ''P. vexans'', formed a

monophyletic In biological cladistics for the classification of organisms, monophyly is the condition of a taxonomic grouping being a clade – that is, a grouping of organisms which meets these criteria: # the grouping contains its own most recent co ...

clade closely related to ''Descolea''. It is likely that the species in this clade will be kept as ''Pholiotina'' species, while the species in the other two clades will be removed to other genera, but this has not happened yet. This study also found some of the sections named by Hausknecht and Krisai-Greilhuber to be

paraphyletic Paraphyly is a taxonomic term describing a grouping that consists of the grouping's last common ancestor and some but not all of its descendant lineages. The grouping is said to be paraphyletic ''with respect to'' the excluded subgroups. In co ...

or polyphyletic.

Notable species

The genus ''Pholiotina'' includes the

psychoactive A psychoactive drug, psychopharmaceutical, mind-altering drug, consciousness-altering drug, psychoactive substance, or psychotropic substance is a chemical substance that alters psychological functioning by modulating central nervous system acti ...

species '' P. cyanopus''. As ''Pholiotina'' was

under its previous definition, many species were subsequently transferred to other genera.

References

{{Taxonbar, from=Q4491390 Bolbitiaceae Agaricales genera Taxa described in 1889