Agaricomycetes
Encyclopedia
Agaricomycetes is a class
of fungi. The taxon
is roughly identical to that defined for the Homobasidiomycetes by Hibbett & Thorn, with the inclusion of Auriculariales
and Sebacinales
. It includes not only mushrooms but also most species placed in the deprecated taxa Gasteromycetes and Homobasidiomycetes. Within the subclass Agaricomycotina
, which already excludes the smut
and rust
fungi, the Agaricomycetes can be further defined by the exclusion of the classes Tremellomycetes
and Dacrymycetes
which are generally considered to be jelly fungi. However, a few former "jelly fungi", such as Auricularia
, are classified in the Agaricomycetes. Agaricomycetes include 17 orders
, 100 families
, 1147 genera
, and 20951 species
.
Although morphology
of the mushroom or fruit body
(basidiocarp) was the basis of early classification of the Agaricomycetes, this is no longer the case. As an example, the distinction between the Gasteromycetes (including puffball
s) and Agaricomycetes (most other agaric
mushrooms) is no longer recognized as a natural one—various puffball species have apparently evolved independently from agaricomycete fungi. However, most mushroom guide books still group the puffballs or gasteroid forms separate from other mushrooms because the older Friesian
classification is still convenient for categorizing fruit body forms. Similarly, modern classifications divide the gasteroid order Lycoperdales
between Agaricales
and Phallales
.
All members of the class produce basidiocarps and these range in size from tiny cups a few millimeters across to a giant polypore
(Fomitiporia ellipsoidea
) greater than several meters across and weighing up to 500 kilograms (1,102.3 lb). The group also includes what are arguably the largest and oldest individual organisms on earth: the mycelium
of Armillaria gallica
have been estimated to extend over 150,000 square metres (37 acres) with a mass of 10,000 kg (22,000 lb) and an age of 1,500 years.
Nearly all species are terrestrial (a few are aquatic), occurring in a wide range of environments where most function as decayers, especially of wood. However, some species are pathogenic or parasitic
, and yet others are symbiotic
, these including the important ectomycorrhizal symbionts of forest trees. General discussions on the forms and life cycles
of these fungi are developed in the article on mushroom
s, in the treatments of the various orders
(links in table at right), and in individual species accounts.
Class (biology)
In biological classification, class is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, order, family, genus, and species, with class fitting between phylum and order...
of fungi. The taxon
Taxon
|thumb|270px|[[African elephants]] form a widely-accepted taxon, the [[genus]] LoxodontaA taxon is a group of organisms, which a taxonomist adjudges to be a unit. Usually a taxon is given a name and a rank, although neither is a requirement...
is roughly identical to that defined for the Homobasidiomycetes by Hibbett & Thorn, with the inclusion of Auriculariales
Auriculariales
The Auriculariales are an order of fungi in the class Agaricomycetes. Species within the order were formerly referred to the "heterobasidiomycetes" or "jelly fungi", since many have gelatinous basidiocarps that produce spores on septate basidia...
and Sebacinales
Sebacinales
The Sebacinales are an order of fungi in the class Agaricomycetes. Taxa have a widespread distribution and are mostly terrestrial, many forming mycorrhizas with a wide variety of plants, including orchids. The order is monotypic, containing a single family, the Sebacinaceae. There are 8 genera and...
. It includes not only mushrooms but also most species placed in the deprecated taxa Gasteromycetes and Homobasidiomycetes. Within the subclass Agaricomycotina
Agaricomycotina
The subphylum Agaricomycotina, also known as the hymenomycetes, is one of three taxa of the fungal division Basidiomycota . The Agaricomycotina contain some 20,000 species, and about 98% of these are in the class Agaricomycetes: most of the fungi known as mushrooms, including the bracket fungi and...
, which already excludes the smut
Smut (fungus)
The smuts are multicellular fungi, that are characterized by their large numbers of teliospores. The smuts get their name from a Germanic word for dirt because of their dark, thick-walled and dust-like teliospores. They are mostly Ustilaginomycetes and can cause plant disease...
and rust
Rust (fungus)
Rusts are plant diseases caused by pathogenic fungi of the order Pucciniales. About 7800 species are known. Rusts can affect a variety of plants; leaves, stems, fruits and seeds. Rust is most commonly seen as coloured powder, composed off tiny aeciospores which land on vegetation producing...
fungi, the Agaricomycetes can be further defined by the exclusion of the classes Tremellomycetes
Tremellomycetes
The Tremellomycetes are a class of dimorphic fungi. Some species have a gelatinous fruiting body or a sacculate parenthesome. There are 3 orders, 11 families, 50 genera, and 377 species in the Tremellomycetes....
and Dacrymycetes
Dacrymycetes
The Dacrymycetes are a class consisting of only one family of jelly fungi, which has imperforate parenthesomes and basidia that are usually branched. There are 9 genera and 101 species in the Dacrymycetaceae family.-References:...
which are generally considered to be jelly fungi. However, a few former "jelly fungi", such as Auricularia
Auricularia
Auricularia is a genus of jelly fungi in the family Auriculariaceae. There are about eight species described in this genus, which has a widespread distribution.-Classification:...
, are classified in the Agaricomycetes. Agaricomycetes include 17 orders
Order (biology)
In scientific classification used in biology, the order is# a taxonomic rank used in the classification of organisms. Other well-known ranks are life, domain, kingdom, phylum, class, family, genus, and species, with order fitting in between class and family...
, 100 families
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
, 1147 genera
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
, and 20951 species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
.
Although morphology
Morphology (biology)
In biology, morphology is a branch of bioscience dealing with the study of the form and structure of organisms and their specific structural features....
of the mushroom or fruit body
Basidiocarp
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 not produce such structures...
(basidiocarp) was the basis of early classification of the Agaricomycetes, this is no longer the case. As an example, the distinction between the Gasteromycetes (including puffball
Puffball
A puffball is a member of any of several groups of fungus in the division Basidiomycota. The puffballs were previously treated as a taxonomic group called the Gasteromycetes or Gasteromycetidae, but they are now known to be a polyphyletic assemblage. The distinguishing feature of all puffballs is...
s) and Agaricomycetes (most other agaric
Agaric
An agaric is a type of fungal fruiting body characterized by the presence of a pileus that is clearly differentiated from the stipe , with lamellae on the underside of the pileus. "Agaric" can also refer to a basidiomycete species characterized by an agaric-type fruiting body...
mushrooms) is no longer recognized as a natural one—various puffball species have apparently evolved independently from agaricomycete fungi. However, most mushroom guide books still group the puffballs or gasteroid forms separate from other mushrooms because the older Friesian
Elias Magnus Fries
-External links:*, Authors of fungal names, Mushroom, the Journal of Wild Mushrooming.*...
classification is still convenient for categorizing fruit body forms. Similarly, modern classifications divide the gasteroid order Lycoperdales
Lycoperdales
The Lycoperdales are a now outdated order of fungi. The order included some well-known types such as the giant puffball, the earthstars, and other tuberous fungi...
between Agaricales
Agaricales
The fungal order Agaricales, also known as gilled mushrooms , or euagarics, contains some of the most familiar types of mushrooms. The order has 33 extant families, 413 genera, and over 13000 described species, along with five extinct genera known only from the fossil record...
and Phallales
Phallales
The Phallales are an order of fungi that is more or less synonymous with the gomphoid-phalloid clade. The order contains two families, the Claustulaceae and the Phallaceae, which collectively contain 26 genera and 88 species.-External links:...
.
All members of the class produce basidiocarps and these range in size from tiny cups a few millimeters across to a giant polypore
Polypore
Polypores are a group of tough, leathery poroid mushrooms similar to boletes, but typically lacking a distinct stalk. The technical distinction between the two types of mushrooms is that polypores do not have the spore-bearing tissue continuous along the entire underside of the mushroom. Many...
(Fomitiporia ellipsoidea
Fomitiporia ellipsoidea
Fomitiporia ellipsoidea is a species of polypore fungus in the family Hymenochaetaceae, a specimen of which produced the largest fruit body ever recorded. Found in China, the fruit bodies produced by the species are brown, woody basidiocarps that grow on dead wood, where the fungus feeds as a...
) greater than several meters across and weighing up to 500 kilograms (1,102.3 lb). The group also includes what are arguably the largest and oldest individual organisms on earth: the mycelium
Mycelium
thumb|right|Fungal myceliaMycelium is the vegetative part of a fungus, consisting of a mass of branching, thread-like hyphae. The mass of hyphae is sometimes called shiro, especially within the fairy ring fungi. Fungal colonies composed of mycelia are found in soil and on or within many other...
of Armillaria gallica
Armillaria gallica
Armillaria gallica is a species of honey mushroom in the Physalacriaceae family of the Agaricales order. The species is a common and ecologically important wood-decay fungus that can live as a saprobe, or as an opportunistic parasite in weakened tree hosts to cause root or butt rot...
have been estimated to extend over 150,000 square metres (37 acres) with a mass of 10,000 kg (22,000 lb) and an age of 1,500 years.
Nearly all species are terrestrial (a few are aquatic), occurring in a wide range of environments where most function as decayers, especially of wood. However, some species are pathogenic or parasitic
Parasitism
Parasitism is a type of symbiotic relationship between organisms of different species where one organism, the parasite, benefits at the expense of the other, the host. Traditionally parasite referred to organisms with lifestages that needed more than one host . These are now called macroparasites...
, and yet others are symbiotic
Symbiosis
Symbiosis is close and often long-term interaction between different biological species. In 1877 Bennett used the word symbiosis to describe the mutualistic relationship in lichens...
, these including the important ectomycorrhizal symbionts of forest trees. General discussions on the forms and life cycles
Biological life cycle
A life cycle is a period involving all different generations of a species succeeding each other through means of reproduction, whether through asexual reproduction or sexual reproduction...
of these fungi are developed in the article on mushroom
Mushroom
A mushroom is the fleshy, spore-bearing fruiting body of a fungus, typically produced above ground on soil or on its food source. The standard for the name "mushroom" is the cultivated white button mushroom, Agaricus bisporus; hence the word "mushroom" is most often applied to those fungi that...
s, in the treatments of the various orders
Order (biology)
In scientific classification used in biology, the order is# a taxonomic rank used in the classification of organisms. Other well-known ranks are life, domain, kingdom, phylum, class, family, genus, and species, with order fitting in between class and family...
(links in table at right), and in individual species accounts.