''Austropaxillus'' 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 ...

fungi A fungus (: fungi , , , or ; or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and mold (fungus), molds, as well as the more familiar mushrooms. These organisms are classified as one ...

in the family

Serpulaceae The Serpulaceae are a family of fungi in the Boletales order. According to the ''Dictionary of the Fungi'' (10th edition, 2008), the family contains 4 genera and 20 species. However, a molecular phylogenetics study showed that the genus '' Neopax ...

, containing nine species found in Australia, New Zealand and South America.

Taxonomy and naming

In 1999, Andreas Bresinsky and colleagues studied the genus ''

Paxillus ''Paxillus'' is a genus of mushrooms of which most are known to be poisonous mushroom, poisonous or inedible. Species include ''Paxillus involutus'' and ''Paxillus vernalis''. Two former species—''Tapinella panuoides'' and ''Tapinella atrotomen ...

'', which appeared to have a centre of diversity in the Southern Hemisphere as a number of species had been described from Australia and New Zealand, and Chile and Argentina in southern South America.

Genetic analysis Genetic analysis is the overall process of studying and researching in fields of science that involve genetics and molecular biology. There are a number of applications that are developed from this research, and these are also considered parts ...

revealed that members of what had been broadly construed as ''Paxillus'' fell into three distinct

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 ...

s. The Southern Hemisphere species were found to be in a lineage that is most closely related to the brown rot genus ''

Serpula ''Serpula'' (also known as calcareous tubeworm, serpulid tubeworm, fanworm, or plume worm) is a genus of sessile, marine annelid tube worms that belongs to the family Serpulidae. Serpulid worms are very similar to tube worms of the closely r ...

''. Supporting this is the finding that the compound 2,4,5-trihydroxyphenylglyoxylic acid has been isolated from members of both ''Austropaxillus'' and ''Serpula''. Hence they moved these species into the new genus ''Austropaxillus''. Later analysis revealed a relationship to '' Gymnopaxillus'', a small genus of

truffle A truffle is the Sporocarp (fungi), fruiting body of a subterranean ascomycete fungus, one of the species of the genus ''Tuber (fungus), Tuber''. More than one hundred other genera of fungi are classified as truffles including ''Geopora'', ''P ...

-like fungi known from south-eastern Australia, Argentina, and Chile. ''Austropaxillus'' and ''Gymnopaxillus'', both

mycorrhiza 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 ...

l genera, form 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 that is

sister A sister is a woman or a girl who shares parents or a parent with another individual; a female sibling. The male counterpart is a brother. Although the term typically refers to a familial relationship, it is sometimes used endearingly to ref ...

to the

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 ...

genus ''Serpula''. Using

molecular clock The molecular clock is a figurative term for a technique that uses the mutation rate of biomolecules to deduce the time in prehistory when two or more life forms diverged. The biomolecular data used for such calculations are usually nucleot ...

analysis, the split between ''Austropaxillus'' and ''Serpula'' has been estimated to have occurred about 34.9 mya, roughly coinciding with the separation of South America and Australia from Antarctica. The prefix ''Austro'' is derived from the

Latin Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...

word ''auster'' "south". 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 ...

is '' Austropaxillus statuum'' from South America.

Description

Morphologically, the

fruit bodies The sporocarp (also known as fruiting body, fruit body or fruitbody) of fungi is a multicellular structure on which spore-producing structures, such as basidia or asci, are borne. The fruitbody is part of the sexual phase of a fungal life cyc ...

of these fungi resemble those of ''Paxillus'', namely they have funnel-shaped

caps Caps are flat headgear. Caps or CAPS may also refer to: Science and technology Computing * CESG Assisted Products Service, provided by the U.K. Government Communications Headquarters * Composite Application Platform Suite, by Java Caps, a Java ...

with inrolled margins and decurrent

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 ...

. In the case of ''Austropaxillus'', the gills are always forked. 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 brown. Microscopically they have long spindle-shaped

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 from 7.8 to 16

μm The micrometre (Commonwealth English as used by the International Bureau of Weights and Measures; SI symbol: μm) or micrometer (American English), also commonly known by the non-SI term micron, is a unit of length in the International System ...

long.

Species

According to the ''Dictionary of the Fungi'' (10th edition, 2008), the genus contains nine species found in the

temperate In geography, the temperate climates of Earth occur in the middle latitudes (approximately 23.5° to 66.5° N/S of the Equator), which span between the tropics and the polar regions of Earth. These zones generally have wider temperature ran ...

Southern Hemisphere. Bresinsky and Jarosch defined the species ''Austropaxillus aurantiacus'' in their 1999 publication on the genus, but this is not a valid name because it is a

homonym In linguistics, homonyms are words which are either; '' homographs''—words that mean different things, but have the same spelling (regardless of pronunciation), or '' homophones''—words that mean different things, but have the same pronunciat ...

of ''Paxillus aurantiacus'' published by

Job Bicknell Ellis Job Bicknell Ellis (January 21, 1829 – December 30, 1905) was a pioneering North American mycologist known for his study of ascomycetes, especially the grouping of fungi called the Pyrenomycetes (known today as the Sordariomycetes). Born and ...

in 1882. It is now known as ''Austropaxillus macnabbii''. Cleland described a ''Paxillus aureus'' and ''P. eucalyptorum'' but no type material or subsequent collections exist.

Ecology

''Austropaxillus'' species form

l relationships with trees of the genus ''

Nothofagus ''Nothofagus'', also known as the southern beeches, is a genus of 43 species of trees and shrubs native to the Southern Hemisphere, found across southern South America (Chile, Argentina) and east and southeast Australia, New Zealand, New Guin ...

'' and less commonly ''

Eucalyptus ''Eucalyptus'' () is a genus of more than 700 species of flowering plants in the family Myrtaceae. Most species of ''Eucalyptus'' are trees, often Mallee (habit), mallees, and a few are shrubs. Along with several other genera in the tribe Eucalyp ...

''.

References

External links

* {{Taxonbar, from=Q4825748 Boletales Boletales genera