''Omphalina'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

of small

agaric An agaric () is a type of fungus 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. In the UK, agarics are called "mushroom ...

s with white,

nonamyloid 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 stai ...

basidiospore A basidiospore is a reproductive spore produced by Basidiomycete fungi, a grouping that includes mushrooms, shelf fungi, rusts, and smuts. Basidiospores typically each contain one haploid nucleus that is the product of meiosis, and they are ...

s and

decurrent ''Decurrent'' (sometimes decurring) is a term used in botany and mycology to describe plant or fungal parts that extend downward. In botany, the term is most often applied to leaf blades that partly wrap or have wings around the stem or petio ...

gills A gill () is a respiratory organ that many aquatic organisms use to extract dissolved oxygen from water and to excrete carbon dioxide. The gills of some species, such as hermit crabs, have adapted to allow respiration on land provided they are ...

. Typically the

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. Caps typically have a visor, or no brim at all. They are popular in casual and informal se ...

has a deep central depression giving the

umbrella An umbrella or parasol is a folding canopy supported by wooden or metal ribs that is usually mounted on a wooden, metal, or plastic pole. It is designed to protect a person against rain or sunlight. The term ''umbrella'' is traditionally use ...

-like to funnel-shaped cap the appearance of a belly button, or a belly with a

navel The navel (clinically known as the umbilicus, commonly known as the belly button or tummy button) is a protruding, flat, or hollowed area on the abdomen at the attachment site of the umbilical cord. All placental mammals have a navel, although ...

. Similarly-shaped agarics are said to be omphalinoid in appearance.

Etymology

''Omphalina'' is the

diminutive A diminutive is a root word that has been modified to convey a slighter degree of its root meaning, either to convey the smallness of the object or quality named, or to convey a sense of intimacy or endearment. A (abbreviated ) is a word-formati ...

of ''Omphalia'' which is a reference to the belly button or

-like appearance of the small dome-shaped caps with a central depression. It derives from the

Greek Greek may refer to: Greece Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group. *Greek language, a branch of the Indo-European language family. **Proto-Greek language, the assumed last common ancestor ...

word omphalos.

Historical nomenclatural confusion

The generic name ''Omphalina'' is an ancient one, linked to the even older mushroom name ''Omphalia'' which cannot be used because it is an illegitimate later homonym. Historically, the former was generally applied to any white-spored, similarly sized and shaped

mushroom A mushroom or toadstool is the fleshy, spore-bearing fruiting body of a fungus, typically produced above ground, on soil, or on its food source. ''Toadstool'' generally denotes one poisonous to humans. The standard for the name "mushroom" is t ...

. As a result, many species that still are labeled ''Omphalina'', or were labeled ''Omphalia'' are in fact not true Omphalinas. The now conserved type species is ''Omphalina pyxidata

http://myconormandie.free.fr/affiche-photo.php?photo=37

Prior to International Code of Botanical Nomenclature, conservation of the type, typification was debated and unstable for several decades.

Phylogenetic redefinition

Molecular

phylogenetic In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups o ...

studies using DNA show this species and others on

moss Mosses are small, non-vascular flowerless plants in the taxonomic division Bryophyta (, ) '' sensu stricto''. Bryophyta (''sensu lato'', Schimp. 1879) may also refer to the parent group bryophytes, which comprise liverworts, mosses, and hor ...

es with reddish brown to yellowish brown

pigment A pigment is a colored material that is completely or nearly insoluble in water. In contrast, dyes are typically soluble, at least at some stage in their use. Generally dyes are often organic compounds whereas pigments are often inorganic compo ...

s that encrust the hyphal walls are related, while many other former Omphalinas are distantly related and are classified in other

orders Order, ORDER or Orders may refer to: * Categorization, the process in which ideas and objects are recognized, differentiated, and understood * Heterarchy, a system of organization wherein the elements have the potential to be ranked a number of d ...

, or

families Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Ideal ...

, and in other genera.

Biology

''Omphalina'' in the modern sense is a small genus of

bryophyte The Bryophyta s.l. are a proposed taxonomic division containing three groups of non-vascular land plants (embryophytes): the liverworts, hornworts and mosses. Bryophyta s.s. consists of the mosses only. They are characteristically limited in ...

colonizing mushrooms. They grow on mossy burned soils and in undisturbed mossy areas in

Arctic The Arctic ( or ) is a polar regions of Earth, polar region located at the northernmost part of Earth. The Arctic consists of the Arctic Ocean, adjacent seas, and parts of Canada (Yukon, Northwest Territories, Nunavut), Danish Realm (Greenla ...

Antarctic The Antarctic ( or , American English also or ; commonly ) is a polar region around Earth's South Pole, opposite the Arctic region around the North Pole. The Antarctic comprises the continent of Antarctica, the Kerguelen Plateau and other ...

alpine Alpine may refer to any mountainous region. It may also refer to: Places Europe * Alps, a European mountain range ** Alpine states, which overlap with the European range Australia * Alpine, New South Wales, a Northern Village * Alpine National Pa ...

and

rural In general, a rural area or a countryside is a geographic area that is located outside towns and cities. Typical rural areas have a low population density and small settlements. Agricultural areas and areas with forestry typically are describ ...

and

urban Urban means "related to a city". In that sense, the term may refer to: * Urban area, geographical area distinct from rural areas * Urban culture, the culture of towns and cities Urban may also refer to: General * Urban (name), a list of people ...

sites. Many other bryophilous mushrooms occur in such habitats but they have other characteristics.

Reclassified and excluded former Omphalinas

Lichenized omphalinas, which are

basidiolichen Basidiolichens are lichenized members of the Basidiomycota, a much smaller group of lichens than the far more common ascolichens in the Ascomycota. In arctic, alpine, and temperate forests, the most common basidiolichens are in the agaric genus ...

s, are now placed in ''

Lichenomphalia ''Lichenomphalia'' is both a basidiolichen and an agaric genus. Most of the species have inconspicuous lichenized thalli that consist of scattered, small, loose, nearly microscopic green balls or foliose small flakes containing single-celled gree ...

''. An example is the species previously known as either ''Omphalina ericetorum'' or ''Omphalina umbellifera'' that is now called ''Lichenomphalia umbellifera''; etc. Bryophilous grey to blackish former omphalinas are largely in the genus '' Arrhenia''. Examples are: ''Omphalina epichysium'', now ''Arrhenia epichysium''; ''Omphalina sphagnicola'' now ''Arrhenia sphagnicola''; etc. Any former omphalina with

amyloid Amyloids are aggregates of proteins characterised by a Fibril, fibrillar morphology of 7–13 Nanometer, nm in diameter, a beta sheet (β-sheet) Secondary structure of proteins, secondary structure (known as cross-β) and ability to be Staining, ...

spores goes into another genus. These genera include ''

Mycena ''Mycena'' is a large genus of small saprotrophic mushrooms that are rarely more than a few centimeters in width. They are characterized by a white spore print, a small conical or bell-shaped cap, and a thin fragile stem. Most are gray or br ...

'', '' Myxomphalia'', ''

Pseudoarmillariella ''Pseudoarmillariella'' is a genus of fungi in the family Hygrophoraceae. The genus contains three species found in Central America, North America, and Asia. ''Pseudoarmillariella'' was described by mycologist Rolf Singer in 1956. See also *Lis ...

'', '' Xeromphalina'', etc. No true ''Omphalina'' has gelatinized or slimy tissues or brightly colored pigments. Neither do they have

cystidia A cystidium (plural 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 ar ...

. Excluded species whose exclusion is supported by molecular analysis, include the genera: '' Blasiphalia'', '' Chrysomphalina'', ''

Chromosera ''Chromosera'' is a genus of fungi in the family Hygrophoraceae. Within the family Hygrophoraceae it is closely related to the genus '' Gloioxanthomyces''. It contains five species. The generic name honors the mycologist Meinhard Moser, and also a ...

'', '' Contumyces'', '' Gerronema'', ''

Haasiella ''Haasiella'' is a fungal genus in the family Hygrophoraceae. It is a monotypic genus that contains only the species ''Haasiella splendidissima''. ''Haasiella venustissima'', formerly considered to be a distinct species based on its one and two-sp ...

'', '' Loreleia'', '' Rickenella'', etc.

Species

*'' Omphalina arctica'' *'' Omphalina chionophila'' *'' Omphalina demissa'' *'' Omphalina favrei'' *''

Omphalina foetida ''Omphalina'' is a genus of small agarics with white, nonamyloid, basidiospores and decurrent gills. Typically the cap has a deep central depression giving the umbrella-like to funnel-shaped cap the appearance of a belly button, or a belly with ...

'' *''

Omphalina fulvopallens ''Omphalina'' is a genus of small agarics with white, nonamyloid, basidiospores and decurrent lamella (mycology), gills. Typically the pileus (mycology), cap has a deep central depression giving the umbrella-like to funnel-shaped cap the appearanc ...

'' *'' Omphalina grisea'' *'' Omphalina kuehneri'' *'' Omphalina mutila'' *'' Omphalina nothofaginea'' *'' Omphalina pseudomuralis'' *''

Omphalina pyxidata ''Omphalina'' is a species of fungus in the family Tricholomataceae, and the type species of the genus ''Omphalina''. It is found in North America and Europe. References External links

* {{Taxonbar, from=Q7090688 Tricholomataceae ...

'' *'' Omphalina rivulicola'' *'' Omphalina subhepatica'' *'' Omphalina wallacei'' *''

Omphalina wellingtonensis ''Omphalina'' is a genus of small agarics with white, nonamyloid, basidiospores and decurrent lamella (mycology), gills. Typically the pileus (mycology), cap has a deep central depression giving the umbrella-like to funnel-shaped cap the appearanc ...

References

{{Taxonbar, from=Q2707211 Tricholomataceae Agaricales genera