Gasteroid fungi
Encyclopedia
The gasteroid fungi are a group of fungi in the Basidiomycota
. Species were formerly placed in the obsolete class
Gasteromycetes Fr. (literally "stomach fungi"), or the equally obsolete order
Gasteromycetales Rea
, because they produce their spores inside their basidiocarps (fruit bodies) rather than on an outer surface. The class is artificial, however, since species—which include puffballs, earthstars, stinkhorns, and false truffles—are not closely related to each other. Because they are often studied as a group, it has been convenient to retain the informal (non-taxonomic
) name of "gasteroid fungi".
L.—were formally described by Linnaeus in his original Species Plantarum of 1753, but the first critical treatment of the group was by Christiaan Hendrik Persoon in his Synopsis methodica fungorum of 1801. Until 1981, this book was the starting point for the naming of Gasteromycetes under the International Code of Nomenclature for algae, fungi, and plants
. Although the starting point was subsequently put back to 1753, names of gasteroid fungi used in Persoon's book are still sanctioned
and cannot be replaced by earlier names. Elias Magnus Fries
introduced the name Gasteromycetes for a class of fungi in his Systema Mycologicum of 1821, although (not using a microscope) he included many species of the Ascomycota
(such as truffles) within the class. Fries contrasted the Gasteromycetes with the Hymenomycetes, where spores are produced externally on gills
, pores, and other surfaces.
This convenient division continued to be used for the next 150 years or so, although by the middle of the twentieth century it had become evident that Gasteromycetes was an artificial class (bringing together a miscellany of unrelated species) and not a natural one. In a 1995 study of British species, Pegler, et al. noted that "these fungi represent an heterogeneous assemblage, a mixture of forms which are derived from various lineages...[they] can be collectively referred to as gasteroid fungi, but they cannot be classified as a single group." DNA-based systematic research has, not unexpectedly, confirmed the diversity of the gasteroid fungi.
In the puffballs, which include the genera Lycoperdon
, Bovista
, and Calvatia
, spores are formed within spherical to pestle-shaped fruit bodies and are released either by wind (as the fruit body wears away, exposing the spore mass inside) or by raindrops. In the latter case, the fruit bodies develop an ostiole
(apical hole) through which spores are puffed out by the pressure of raindrops falling on the fruit body surface. The same ingenious mechanism has evolved separately in the earthstars (Geastrum
species), which have a hard outer layer to the fruitbody that splits open in a star-like manner to reveal the puffball-like spore sack.
The stinkhorns and their allies, including the genera Phallus
, Mutinus
, Clathrus
, and Lysurus
, form spores within internally gelatinous, puffball-like 'eggs'. At maturity the eggs split and various strange spore-receptacles emerge. The spores are coated with an evil-smelling slime that attracts flies—these being the agents of dispersal.
The bird's nest fungi, which include the genera Cyathus
and Crucibulum
, form miniature, egg-like packets of spores within cup-shaped fruit bodies. These packets of spores are ejected by rain-splash and may land some distance away, the packets gradually wearing away to release the spores themselves.
False truffles in such genera as Rhizopogon
, Hymenogaster
, and Melanogaster
develop underground or at the soil surface. As with the true truffles, some of them have distinctive smells and are actively hunted out by small mammals which may consume them and spread their spores. Some New Zealand secotioid
fungi in the genus Leratiomyces
are shaped and coloured like berries and their spores may be dispersed by ground-dwelling birds.
Most gasteroid fungi are saprotrophic, living on dead plant material, including very rotten, fallen wood.
The earthballs (Scleroderma
species), dyeballs (Pisolithus
species), and many false truffles are ectomycorrhizal, forming a mutually beneficial relationship with the roots of living trees.
These species are cosmopolitan
, but the stinkhorns and their allies are most diverse in the wet tropics.
Producing spores in an enclosed fruit body is a suitable adaptation for growing in arid conditions. Several genera, including Podaxis
, Battarrea
, Phellorinia
, and Tulostoma
, are typical of steppe
s and deserts, some also occurring in sand dunes in temperate
zones.
Basidiomycota
Basidiomycota is one of two large phyla that, together with the Ascomycota, comprise the subkingdom Dikarya within the Kingdom Fungi...
. Species were formerly placed in the obsolete class
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...
Gasteromycetes Fr. (literally "stomach fungi"), or the equally obsolete order
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...
Gasteromycetales Rea
Carleton Rea
Carleton Rea was an English mycologist, botanist, and naturalist.-Background and education:Carleton Rea was born in Worcester, the son of the City Coroner. He was educated at The King's School and Magdalen College, Oxford, where he studied law...
, because they produce their spores inside their basidiocarps (fruit bodies) rather than on an outer surface. The class is artificial, however, since species—which include puffballs, earthstars, stinkhorns, and false truffles—are not closely related to each other. Because they are often studied as a group, it has been convenient to retain the informal (non-taxonomic
Taxonomy
Taxonomy is the science of identifying and naming species, and arranging them into a classification. The field of taxonomy, sometimes referred to as "biological taxonomy", revolves around the description and use of taxonomic units, known as taxa...
) name of "gasteroid fungi".
History
Several gasteroid fungi—such as the stinkhorn, Phallus impudicusPhallus impudicus
Phallus impudicus, known colloquially as the common stinkhorn, is a widespread fungus recognizable for its foul odor and its phallic shape when mature, the latter feature giving rise to several names in 17th-century England. It is a common mushroom in Europe and western North America, where it...
L.—were formally described by Linnaeus in his original Species Plantarum of 1753, but the first critical treatment of the group was by Christiaan Hendrik Persoon in his Synopsis methodica fungorum of 1801. Until 1981, this book was the starting point for the naming of Gasteromycetes under the International Code of Nomenclature for algae, fungi, and plants
International Code of Nomenclature for algae, fungi, and plants
The International Code of Nomenclature for algae, fungi, and plants is the set of rules and recommendations dealing with the formal botanical names that are given to plants, fungi and a few other groups of organisms, all those "traditionally treated as plants"., Preamble, para...
. Although the starting point was subsequently put back to 1753, names of gasteroid fungi used in Persoon's book are still sanctioned
Sanctioned name
In mycology, a sanctioned name is a name that was adopted in certain works of Christiaan Hendrik Persoon or Elias Magnus Fries, which are considered major points in fungal taxonomy.-Definition and effects:...
and cannot be replaced by earlier names. Elias Magnus Fries
Elias Magnus Fries
-External links:*, Authors of fungal names, Mushroom, the Journal of Wild Mushrooming.*...
introduced the name Gasteromycetes for a class of fungi in his Systema Mycologicum of 1821, although (not using a microscope) he included many species of the Ascomycota
Ascomycota
The Ascomycota are a Division/Phylum of the kingdom Fungi, and subkingdom Dikarya. Its members are commonly known as the Sac fungi. They are the largest phylum of Fungi, with over 64,000 species...
(such as truffles) within the class. Fries contrasted the Gasteromycetes with the Hymenomycetes, where spores are produced externally on gills
Pileus (mycology)
The pileus is the technical name for the cap, or cap-like part, of a basidiocarp or ascocarp that supports a spore-bearing surface, the hymenium. The hymenium may consist of lamellae, tubes, or teeth, on the underside of the pileus...
, pores, and other surfaces.
This convenient division continued to be used for the next 150 years or so, although by the middle of the twentieth century it had become evident that Gasteromycetes was an artificial class (bringing together a miscellany of unrelated species) and not a natural one. In a 1995 study of British species, Pegler, et al. noted that "these fungi represent an heterogeneous assemblage, a mixture of forms which are derived from various lineages...[they] can be collectively referred to as gasteroid fungi, but they cannot be classified as a single group." DNA-based systematic research has, not unexpectedly, confirmed the diversity of the gasteroid fungi.
Description and genera
The gasteroid fungi form visibly diverse fruit bodies, but in all cases the spores are formed and reach maturity internally. They are not discharged forcibly, as in agarics and most other members of the Basidiomycota, but are released passively in a variety of different ways.In the puffballs, which include the genera Lycoperdon
Lycoperdon
Lycoperdon is a genus of puffball mushrooms. The genus has a widespread distribution and contains about 50 species. In general, it contains the smaller species such as the pear shaped puffball and the gem studded puffball. Most of the time they grow from dead wood and if they grow through the...
, Bovista
Bovista
Bovista is a genus of fungi in the family Agaricaceae, commonly known as the true puffballs. It was formerly classified within the now-obsolete order Lycoperdales, which, following a restructuring of fungal taxonomy brought about by molecular phylogeny, has been split; the species of Bovista are...
, and Calvatia
Calvatia
Calvatia is a genus of puffball mushrooms which includes the spectacular giant puffball C. gigantea. It was formerly classified within the now-obsolete order Lycoperdales, which, following a restructuring of fungal taxonomy brought about by molecular phylogeny, has been split; the puffballs,...
, spores are formed within spherical to pestle-shaped fruit bodies and are released either by wind (as the fruit body wears away, exposing the spore mass inside) or by raindrops. In the latter case, the fruit bodies develop an ostiole
Ostiole
An ostiole is a small hole or opening through which algae or ascomycetal fungi release their mature spores. The term is also used in higher plants, for example to denote the opening of the involuted fig inflorescence through which fig wasps enter to pollinate and breed....
(apical hole) through which spores are puffed out by the pressure of raindrops falling on the fruit body surface. The same ingenious mechanism has evolved separately in the earthstars (Geastrum
Geastrum
Geastrum is a genus of mushroom in the family Geastraceae. Many species are known commonly as earthstars.The name comes from geo meaning earth and aster meaning star....
species), which have a hard outer layer to the fruitbody that splits open in a star-like manner to reveal the puffball-like spore sack.
The stinkhorns and their allies, including the genera Phallus
Phallus (genus)
The genus Phallus, commonly known as stinkhorns, are a group of basidiomycetes which produce a foul-scented, phallic mushroom, from which their name is derived. The genus has a widespread distribution and, according to a 2008 estimate, contains 18 species. They belong to the family Phallaceae in...
, Mutinus
Mutinus
Mutinus is a genus of fungi in the family Phallaceae. The genus was first described by Elias Magnus Fries in 1849. According to the Dictionary of the Fungi , the widespread genus contains 12 species.-Species:...
, Clathrus
Clathrus
Clathrus is a genus of basidiomycete fungi of the family Phallaceae. As with other stinkhorn fungi, mature fruit bodies are covered with olive-brown slimy gleba, containing spores, which attracts flies...
, and Lysurus
Lysurus (fungus)
Lysurus is a genus of fungi in the Phallaceae, a family known collectively as the stinkhorn fungi. The species have a widespread distribution, but are specially prevalent in tropical areas. The fruit bodies of Lysurus fungi are characterized by having short, thick arms which are upright, and may...
, form spores within internally gelatinous, puffball-like 'eggs'. At maturity the eggs split and various strange spore-receptacles emerge. The spores are coated with an evil-smelling slime that attracts flies—these being the agents of dispersal.
The bird's nest fungi, which include the genera Cyathus
Cyathus
Cyathus is a genus of fungi in the Nidulariaceae, a family collectively known as the bird's nest fungi. They are given this name since they resemble tiny bird's nests filled with "eggs", structures large enough to have been mistaken in the past for seeds. However, these are now known to be...
and Crucibulum
Crucibulum
Crucibulum is a genus in the Nidulariaceae, a family of fungi whose fruiting bodies resemble tiny egg-filled bird's nests. Often called "splash cups", the fruiting bodies are adapted for spore dispersal by using the kinetic energy of falling drops of rain...
, form miniature, egg-like packets of spores within cup-shaped fruit bodies. These packets of spores are ejected by rain-splash and may land some distance away, the packets gradually wearing away to release the spores themselves.
False truffles in such genera as Rhizopogon
Rhizopogon
Rhizopogon is a genus of hypogeous Basidiomycetes. Recent micromorphological and molecular phylogenetic study has established that Rhizopogon is a member of the Boletales, closely related to Suillus. All species of Rhizopogon are ectomycorrhizal and are thought to play an important role in the...
, Hymenogaster
Hymenogaster
Hymenogaster is a genus of fungi in the Hymenogastraceae family. The genus has a widespread distribution, especially in temperate regions, and contains about 100 species. The taxonomy of the European species has recently been revised, and twelve species were recognized, for which an identification...
, and Melanogaster
Melanogaster (fungus)
Melanogaster is a genus of fungus that resemble truffles, and are often mistaken for them. However, they do not have the characteristic aroma and value of truffles, and may even be poisonous...
develop underground or at the soil surface. As with the true truffles, some of them have distinctive smells and are actively hunted out by small mammals which may consume them and spread their spores. Some New Zealand secotioid
Secotioid
Secotioid fungi are an intermediate growth form between mushroom-like hymenomycetes and closed bag-shaped gasteromycetes, where an evolutionary process of gasteromycetation has started but not run to completion...
fungi in the genus Leratiomyces
Leratiomyces
Leratiomyces is a genus of mushroom-forming basidiomycetes first described in 2008. It includes several formerly described, variously, from the genera Stropharia, Hypholoma, and Weraroa...
are shaped and coloured like berries and their spores may be dispersed by ground-dwelling birds.
Habitat and distribution
The earthballs (Scleroderma
Scleroderma (genus)
Scleroderma is a genus of fungi, commonly known as earth balls, now known to belong to the Boletales order, in suborder Sclerodermatineae.. The best known species are S. citrinum and S. verrucosum...
species), dyeballs (Pisolithus
Pisolithus
Pisolithus is a genus of fungi within the Sclerodermataceae family . The type species, P. arenarius, is now known to be synonymous with P. arhizus.-Species:*Pisolithus abditus*Pisolithus albus...
species), and many false truffles are ectomycorrhizal, forming a mutually beneficial relationship with the roots of living trees.
These species are cosmopolitan
Cosmopolitan distribution
In biogeography, a taxon is said to have a cosmopolitan distribution if its range extends across all or most of the world in appropriate habitats. For instance, the killer whale has a cosmopolitan distribution, extending over most of the world's oceans. Other examples include humans, the lichen...
, but the stinkhorns and their allies are most diverse in the wet tropics.
Producing spores in an enclosed fruit body is a suitable adaptation for growing in arid conditions. Several genera, including Podaxis
Podaxis
Podaxis is a genus of secotioid fungi in the family Agaricaceae. Species, which have the appearance of a "stalked-puffball", have a worldwide distribution, and tend to be found growing solitary or scattered on sandy soils, especially in arid regions...
, Battarrea
Battarrea
Battarrea is a genus of mushrooms in the Tulostomataceae family.-Species list:*Battarrea arenicola Copel. *Battarrea franciscana Copel. *Battarrea gaudichaudii Mont. *Battarrea guachiparum Speg....
, Phellorinia
Phellorinia
Phellorinia is a genus of fungi in the Phelloriniaceae family of the Agaricales order. The genus is monotypic, and contains the single species Phellorinia herculeana, described by English naturalist Miles Joseph Berkeley in 1843 as P. inquinans....
, and Tulostoma
Tulostoma
Tulostoma is a genus of fungi in the family Agaricaceae.-External links:* at Index Fungorum...
, are typical of steppe
Steppe
In physical geography, steppe is an ecoregion, in the montane grasslands and shrublands and temperate grasslands, savannas, and shrublands biomes, characterized by grassland plains without trees apart from those near rivers and lakes...
s and deserts, some also occurring in sand dunes in temperate
Temperate
In geography, temperate or tepid latitudes of the globe lie between the tropics and the polar circles. The changes in these regions between summer and winter are generally relatively moderate, rather than extreme hot or cold...
zones.