Geastrum triplex
Encyclopedia
Geastrum triplex is an inedible fungus
which is found in the detritus
and leaf litter of hardwood forests in many parts of the world. It is commonly known as the collared earthstar, the saucered earthstar, or the triple earthstar—and less commonly by the alternative species name Geastrum indicum. It is the largest member of the genus
Geastrum (or earthstar fungi
) and expanded mature specimens can reach a tip-to-tip length of up to 12 centimetres (4.7 in).
Immature fruit bodies
are spherical—somewhat resembling puffball
s with pointed beaks—and are partially or completely buried in the ground. As the fungus matures, the outer layer of tissue (the exoperidium
) splits into four to eight pointed segments that spread outwards and downwards, lifting and exposing the spherical inner spore
sac. The spore sac contains the gleba
, a mass of spores and fertile mycelial
tissue that when young is white and firm, but ages to become brown and powdery. Often, a layer of the exoperidium splits around the perimeter of the spore sac so that it appears to rest in a collar or saucer. Atop the spore sac is a small pointed beak, the peristome
, which has a small hole from which spores
may be released.
The species is widespread and can be found in Asia, Australasia, Europe, and both North and South America. The fungus has a history of use in the traditional medicine
s of native North America
and China. Fruit bodies have been analyzed chemically
to determine their lipid
content, and various chemical derivatives
of the fungal sterol ergosterol
have been identified.
, as Geaster triplex in 1840. The earlier genus name Geaster, introduced by Italian botanist Pier Antonio Micheli
in 1727 in Nova Plantarum Genera, is considered an orthographical variant of Geastrum. Junghuhn, who was living in Indonesia and extensively surveyed its fungal flora, discovered the type specimen on Mount Panggerangi
on the island Java
, at an elevation between 3000 to 5000 ft (914.4 to 1,524 m). Today, the type specimen is kept at the National Herbarium of the Netherlands
in Leiden. The morphological
feature used by Junghuhn to differentiate G. triplex from other similar earthstars was the collar-like structure of the inner layer of the exoperidium
. American mycologist Curtis Gates Lloyd
would later erroneously suggest that the species was a "giant form" of Geastrum saccatum
.
Several authors have regarded Geastrum indicum as the correct name for G. triplex. This is because G. indicum—a species described by Johann Friedrich Klotzsch
in 1832 as Cycloderma indicum and then moved to Geastrum by Stephan Rauschert in 1959—may be the same species as Geastrum triplex. If it is in fact the same species, the first published name (i.e., G. indicum) has nomenclatorial
priority according to the rules of the International Code of Botanical Nomenclature. More recently, several authors argue that G. indicum should be rejected as a nomen dubium
and G. triplex maintained as the correct name for the species.
Stellan Sunhede's 1989 monograph
of European species of Geastrum follows V. J. Staněk's concept for the infrageneric (below the level of genus) placement of Geastrum, and places G. triplex with species that do not incorporate and encrust forest debris (section Basimyceliata). G. triplex is further categorized in subsection Laevistomata, which includes species with a fibrillose peristome—that is, made of parallel, thin, thread-like filaments. Within subsection Laevistomata it is in stirps Triplex, due to its delimited (with a distinct restricting edge) or irregularly torn peristome.
The specific epithet triplex means "threefold", and refers to the three-layered peridium
. Geastrum triplex has acquired several vernacular names
, including the collared earthstar, the saucered earthstar, and the triple earthstar.
s, the fruit body
of Geastrum triplex is the visible part of a larger organism. Hidden from sight are masses of nearly invisible fungal threads called mycelium
, which form the active feeding and growing structures of the fungus. The fruit body—created when environmental conditions such as temperature, moisture, and nutrient availability are optimal—is designed to produce and disseminate spore
s. Geastrum triplex has the largest fruit body of the earthstar
mushrooms. The immature fruit body is typically 1 to 5 cm (0.393700787401575 to 2 in) in diameter, and up to 8 to 9 cm (3.1 to 3.5 in) broad (Roody gives a larger value here, up to 11.5 cm) after the rays have spread out. It is composed of a roughly spherical to egg-shaped structure, the endoperidium, topped by an opening, the ostiole
, covered by fragments of tissue that form a small pointed beak (a peristome). The endoperidium is typically lacking any sort of stem (it is sessile
) grayish-brown to "wood brown" when young but light yellow-brown in dried, unopened specimens. The outer tissue layer, the exoperidium, develops splits which radiate from the apex and form between four and eight rays that separate from the endoperidium. The latter's thin and papery envelope surrounds a mass of spores and fertile tissue known as the gleba
. The central part of the gleba contains a pseudocolumella (a columella not attached to the stalk), that is typically cylindrical or club-shaped, and extends up from the base. Because of the variability in columella persistence, size, structure and shape within the genus, its value for identification is limited.
The exoperidium's rays are 2 to 4 cm (0.78740157480315 to 1.6 in) long and up to 4 mm (3/16 in) thick. The outer surface of the rays (the lower surface, after expansion) and unopened specimens have a rough texture. In several Geastrum species, dirt and debris adhere to the underside, this is not the case in G. triplex. The inner fleshy layers (upper surface) of these rays are near "wood brown" in color when dried, and have a layer of surface tissue that cracks into patches. There is a great deal of variation, however, to the extent in which the upper surface tissue of the rays crack: this tissue layer may also remain closely attached as a sheet over the unsegmented part of the outer wall with the part adhering to the rays variously cracked and sometimes finally peeling off in places.
In G. triplex, the bases of the rays usually break around the perimeter of the endoperidium to form a saucerlike platform or receptacle in which the endoperidium rests. However, not all specimens form this receptacle, leading to possible confusion with other Geastrum species. Curtis Gates Lloyd
claimed that in tropical regions, with an abundance of high temperatures and humidity, the fungus expands rapidly, which is more conducive to the fleshy layer breaking away to form a receptacle; in more temperate
areas this effect would not be as pronounced and "usually does not occur at all".
The endoperidium is 1 to 3 cm (0.393700787401575 to 1.2 in) in diameter by 0.9 to 2 cm (0.354330708661417 to 0.78740157480315 in) high, sessile, and a dull grayish-brown. The peristome is made of radially arranged fibrils that clump together at the apex in groups of unequal length to form an opening that appears jagged or torn. The circular area bordering the peristome is a paler color. Spores are thought to be dispersed by the wind sucking them out when it blows over the hole, or when falling raindrops hit the flexible endoperidium, creating a puff of air that forces the spores through the ostiole.
, which is composed of a pseudocolumella, unbranched threads (the capillitium), the spore-bearing cells (basidia) and the spores
themselves; all of these microscopic elements have certain characteristic features that help distinguish G. triplex from other superficially similar earthstars.
The spores are spherical, and 3.5–4.5 µm
in diameter. They are covered with short narrow abruptly terminating projections of a translucent (hyaline
) substance, which turn a pale cinnamon brown in potassium hydroxide
, and a dark dull brown (nearly sepia
) when stained with iodine
. The capillitium is made of what appears to be encrusted cylindrical filaments 3–6 µm in diameter, of a color varying from hyaline to dull yellowish brown in potassium hydroxide
, and yellowish in iodine
; its walls are thickened to the point where the interior (lumen
) appears as only a line. Either two or four spores are attached to the basidia, and the sterigmata (extensions of the basidia that attach the spores) are long, up to 20 µm. Geastrum triplex does not have cystidia.
or G. fimbriatum
, as the rays do not always crack around the perimeter to form a bowl under the spore case. However, it is larger than either of these species. The combination of characteristics which distinguish G. triplex from other earthstars include the lack of debris adhering to the outer surfaces, the saucer-like base in which the spore case is seated, the relatively large size, the fibrillose peristome and the paler area surrounding the peristome separating it from the rest of the endoperidium. Unlike some other Geastrum species, the rays of G. triplex are not hygroscopic: they do not open and close in response to changes in humidity.
. Fruit bodies are often found around well-rotted tree stumps; they are initially almost buried in the loose duff
, but emerge during maturity as the downward curling of the rays exposes the spore sac. Old fruit bodies are persistent, and may survive the winter to be found the following spring or summer. A Dutch study reported a propensity for G. triplex to grow on soil made calcium
-rich from washed-out chalk
of crushed shells on bicycling paths. It is described as common in North America and Europe. One author states it is commonly found under beech
trees.
Geastrum triplex has a widespread distribution, and has been collected in Asia (China, Korea Iran, and Turkey), Australia, Europe (Belgium, Czech Republic, Sweden, and the Canary Islands), and Africa (Congo, South Africa). In North America, its range extends north to Canada and south to Mexico, including the whole continental United States and Hawaii. In Central and South America the fungus has been reported from Panama, Trinidad and Tobago, Argentina, Brazil, and Chile.
says that they are reputed to be edible
when immature—when the gleba is still white and firm—but adds that they are rarely found in this form.
called them ka-ka-toos, meaning "fallen stars", and according to legend, they were an indication of supernatural events. The Cherokee
put fruit bodies on the navels of babies after childbirth until the withered umbilical cord fell off, "both as a prophylactic and a therapeutic measure". In traditional Chinese medicine
, G. triplex is used to reduce inflammation
in the respiratory tract, and to staunch bleeding and reduce swelling.
and shown to contain a number of bioactive compounds, including fungal sterol
s such as ergosta-4,6,8,(14),22-tetraen-3-one,5,6-dihydroergosterol, ergosterol
, and peroxyergosterol. The fungus also contains various fatty acid
s, notably myristic
, palmitic
, stearic
, oleic
, alpha-linolenic
, and linoeic acid.
Fungus
A fungus is a member of a large group of eukaryotic organisms that includes microorganisms such as yeasts and molds , as well as the more familiar mushrooms. These organisms are classified as a kingdom, Fungi, which is separate from plants, animals, and bacteria...
which is found in the detritus
Detritus
Detritus is a biological term used to describe dead or waste organic material.Detritus may also refer to:* Detritus , a geological term used to describe the particles of rock produced by weathering...
and leaf litter of hardwood forests in many parts of the world. It is commonly known as the collared earthstar, the saucered earthstar, or the triple earthstar—and less commonly by the alternative species name Geastrum indicum. It is the largest member of the genus
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...
Geastrum (or earthstar fungi
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....
) and expanded mature specimens can reach a tip-to-tip length of up to 12 centimetres (4.7 in).
Immature fruit bodies
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...
are spherical—somewhat resembling 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 with pointed beaks—and are partially or completely buried in the ground. As the fungus matures, the outer layer of tissue (the exoperidium
Peridium
The peridium is the protective layer that encloses a mass of spores in fungi. This outer covering is a distinctive feature of the Gasteromycetes.-Description:...
) splits into four to eight pointed segments that spread outwards and downwards, lifting and exposing the spherical inner spore
Spore
In biology, a spore is a reproductive structure that is adapted for dispersal and surviving for extended periods of time in unfavorable conditions. Spores form part of the life cycles of many bacteria, plants, algae, fungi and some protozoa. According to scientist Dr...
sac. The spore sac contains the gleba
Gleba
Gleba is the fleshy spore-bearing inner mass of fungi such as the puffball or stinkhorn.The gleba is a solid mass of spores, generated within an enclosed area within the sporocarp. The continuous maturity of the sporogenous cells leave the spores behind as a powdery mass that can be easily blown away...
, a mass of spores and fertile mycelial
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...
tissue that when young is white and firm, but ages to become brown and powdery. Often, a layer of the exoperidium splits around the perimeter of the spore sac so that it appears to rest in a collar or saucer. Atop the spore sac is a small pointed beak, the peristome
Peristome
The word peristome is derived from the Greek peri, meaning 'around' or 'about', and stoma, 'mouth'. It is a term used to describe various anatomical features that surround an opening to an organ or structure. The term is used in plants and invertebrate animals, such as in describing the shells of...
, which has a small hole from which spores
Basidiospore
A basidiospore is a reproductive spore produced by Basidiomycete fungi. Basidiospores typically each contain one haploid nucleus that is the product of meiosis, and they are produced by specialized fungal cells called basidia. In grills under a cap of one common species in the phylum of...
may be released.
The species is widespread and can be found in Asia, Australasia, Europe, and both North and South America. The fungus has a history of use in the traditional medicine
Traditional medicine
Traditional medicine comprises unscientific knowledge systems that developed over generations within various societies before the era of modern medicine...
s of native North America
Indigenous peoples of the Americas
The indigenous peoples of the Americas are the pre-Columbian inhabitants of North and South America, their descendants and other ethnic groups who are identified with those peoples. Indigenous peoples are known in Canada as Aboriginal peoples, and in the United States as Native Americans...
and China. Fruit bodies have been analyzed chemically
Analytical chemistry
Analytical chemistry is the study of the separation, identification, and quantification of the chemical components of natural and artificial materials. Qualitative analysis gives an indication of the identity of the chemical species in the sample and quantitative analysis determines the amount of...
to determine their lipid
Lipid
Lipids constitute a broad group of naturally occurring molecules that include fats, waxes, sterols, fat-soluble vitamins , monoglycerides, diglycerides, triglycerides, phospholipids, and others...
content, and various chemical derivatives
Derivative (chemistry)
In chemistry, a derivative is a compound that is derived from a similar compound by some chemical or physical process. In the past it was also used to mean a compound that can be imagined to arise from another compound, if one atom is replaced with another atom or group of atoms, but modern...
of the fungal sterol ergosterol
Ergosterol
Ergosterol is a sterol found in fungi, and named for ergot, a common name for the members of the fungal genus Claviceps from which ergosterol was first isolated. Ergosterol does not occur in plant or animal cells...
have been identified.
Taxonomy and classification
The species was first described scientifically, by German botanist Franz Wilhelm JunghuhnFranz Wilhelm Junghuhn
Friedrich Franz Wilhelm Junghuhn , was a German botanist. His father, Friedrich Junghuhn was a barber and a surgeon. His mother was Christine Marie Schiele. Junghuhn studied medicine in Halle and in Berlin from 1827 to 1831, meanwhile publishing a seminal paper on mushrooms in Limnaea...
, as Geaster triplex in 1840. The earlier genus name Geaster, introduced by Italian botanist Pier Antonio Micheli
Pier Antonio Micheli
Pier Antonio Micheli was a noted Italian botanist, professor of botany in Pisa, curator of the Orto Botanico di Firenze, author of Nova plantarum genera iuxta Tournefortii methodum disposita...
in 1727 in Nova Plantarum Genera, is considered an orthographical variant of Geastrum. Junghuhn, who was living in Indonesia and extensively surveyed its fungal flora, discovered the type specimen on Mount Panggerangi
Mount Gede
Mount Gede or Gunung Gede is a stratovolcano in West Java, Indonesia. The volcano contains two peaks with Mount Gede as one peak and Mount Pangrango for the other one. Three major cities, Cianjur, Sukabumi and Bogor, are located in the volcano complex at the east, south and northwest, respectively...
on the island Java
Java
Java is an island of Indonesia. With a population of 135 million , it is the world's most populous island, and one of the most densely populated regions in the world. It is home to 60% of Indonesia's population. The Indonesian capital city, Jakarta, is in west Java...
, at an elevation between 3000 to 5000 ft (914.4 to 1,524 m). Today, the type specimen is kept at the National Herbarium of the Netherlands
National Herbarium of the Netherlands
The National Herbarium of the Netherlands was established in 1999 through a decentralized merger of the major university herbaria of Leiden , Utrecht and Wageningen...
in Leiden. The morphological
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....
feature used by Junghuhn to differentiate G. triplex from other similar earthstars was the collar-like structure of the inner layer of the exoperidium
Peridium
The peridium is the protective layer that encloses a mass of spores in fungi. This outer covering is a distinctive feature of the Gasteromycetes.-Description:...
. American mycologist Curtis Gates Lloyd
Curtis Gates Lloyd
Curtis Gates Lloyd was an American mycologist known for both his research on the Gasteromycetes, as well as his controversial views on naming conventions in taxonomy. He had a herbarium with over 59,000 fungal specimens, and published over a thousand new species of fungi...
would later erroneously suggest that the species was a "giant form" of Geastrum saccatum
Geastrum saccatum
Geastrum saccatum, commonly known as the rounded earthstar, is a species of mushroom belonging in the Geastrum genus. It is found in North America and Europe and is found growing on rotting wood. It is considered inedible by mushroomers, because of its bitter taste. It is a common mushroom, but...
.
Several authors have regarded Geastrum indicum as the correct name for G. triplex. This is because G. indicum—a species described by Johann Friedrich Klotzsch
Johann Friedrich Klotzsch
Johann Friedrich Klotzsch was a German pharmacist and botanist.His principal work was in the field of mycology, with the study and description of many species of mushroom.-Selected works:...
in 1832 as Cycloderma indicum and then moved to Geastrum by Stephan Rauschert in 1959—may be the same species as Geastrum triplex. If it is in fact the same species, the first published name (i.e., G. indicum) has nomenclatorial
Binomial nomenclature
Binomial nomenclature is a formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin grammatical forms, although they can be based on words from other languages...
priority according to the rules of the International Code of Botanical Nomenclature. More recently, several authors argue that G. indicum should be rejected as a nomen dubium
Nomen dubium
In zoological nomenclature, a nomen dubium is a scientific name that is of unknown or doubtful application...
and G. triplex maintained as the correct name for the species.
Stellan Sunhede's 1989 monograph
Monograph
A monograph is a work of writing upon a single subject, usually by a single author.It is often a scholarly essay or learned treatise, and may be released in the manner of a book or journal article. It is by definition a single document that forms a complete text in itself...
of European species of Geastrum follows V. J. Staněk's concept for the infrageneric (below the level of genus) placement of Geastrum, and places G. triplex with species that do not incorporate and encrust forest debris (section Basimyceliata). G. triplex is further categorized in subsection Laevistomata, which includes species with a fibrillose peristome—that is, made of parallel, thin, thread-like filaments. Within subsection Laevistomata it is in stirps Triplex, due to its delimited (with a distinct restricting edge) or irregularly torn peristome.
The specific epithet triplex means "threefold", and refers to the three-layered peridium
Peridium
The peridium is the protective layer that encloses a mass of spores in fungi. This outer covering is a distinctive feature of the Gasteromycetes.-Description:...
. Geastrum triplex has acquired several vernacular names
Common name
A common name of a taxon or organism is a name in general use within a community; it is often contrasted with the scientific name for the same organism...
, including the collared earthstar, the saucered earthstar, and the triple earthstar.
Description
Like all mushroomMushroom
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, the 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...
of Geastrum triplex is the visible part of a larger organism. Hidden from sight are masses of nearly invisible fungal threads called 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...
, which form the active feeding and growing structures of the fungus. The fruit body—created when environmental conditions such as temperature, moisture, and nutrient availability are optimal—is designed to produce and disseminate spore
Spore
In biology, a spore is a reproductive structure that is adapted for dispersal and surviving for extended periods of time in unfavorable conditions. Spores form part of the life cycles of many bacteria, plants, algae, fungi and some protozoa. According to scientist Dr...
s. Geastrum triplex has the largest fruit body of the earthstar
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....
mushrooms. The immature fruit body is typically 1 to 5 cm (0.393700787401575 to 2 in) in diameter, and up to 8 to 9 cm (3.1 to 3.5 in) broad (Roody gives a larger value here, up to 11.5 cm) after the rays have spread out. It is composed of a roughly spherical to egg-shaped structure, the endoperidium, topped by an opening, the 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....
, covered by fragments of tissue that form a small pointed beak (a peristome). The endoperidium is typically lacking any sort of stem (it is sessile
Sessility (botany)
In botany, sessility is a characteristic of plants whose flowers or leaves are borne directly from the stem or peduncle, and thus lack a petiole or pedicel...
) grayish-brown to "wood brown" when young but light yellow-brown in dried, unopened specimens. The outer tissue layer, the exoperidium, develops splits which radiate from the apex and form between four and eight rays that separate from the endoperidium. The latter's thin and papery envelope surrounds a mass of spores and fertile tissue known as the gleba
Gleba
Gleba is the fleshy spore-bearing inner mass of fungi such as the puffball or stinkhorn.The gleba is a solid mass of spores, generated within an enclosed area within the sporocarp. The continuous maturity of the sporogenous cells leave the spores behind as a powdery mass that can be easily blown away...
. The central part of the gleba contains a pseudocolumella (a columella not attached to the stalk), that is typically cylindrical or club-shaped, and extends up from the base. Because of the variability in columella persistence, size, structure and shape within the genus, its value for identification is limited.
The exoperidium's rays are 2 to 4 cm (0.78740157480315 to 1.6 in) long and up to 4 mm (3/16 in) thick. The outer surface of the rays (the lower surface, after expansion) and unopened specimens have a rough texture. In several Geastrum species, dirt and debris adhere to the underside, this is not the case in G. triplex. The inner fleshy layers (upper surface) of these rays are near "wood brown" in color when dried, and have a layer of surface tissue that cracks into patches. There is a great deal of variation, however, to the extent in which the upper surface tissue of the rays crack: this tissue layer may also remain closely attached as a sheet over the unsegmented part of the outer wall with the part adhering to the rays variously cracked and sometimes finally peeling off in places.
In G. triplex, the bases of the rays usually break around the perimeter of the endoperidium to form a saucerlike platform or receptacle in which the endoperidium rests. However, not all specimens form this receptacle, leading to possible confusion with other Geastrum species. Curtis Gates Lloyd
Curtis Gates Lloyd
Curtis Gates Lloyd was an American mycologist known for both his research on the Gasteromycetes, as well as his controversial views on naming conventions in taxonomy. He had a herbarium with over 59,000 fungal specimens, and published over a thousand new species of fungi...
claimed that in tropical regions, with an abundance of high temperatures and humidity, the fungus expands rapidly, which is more conducive to the fleshy layer breaking away to form a receptacle; in more 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...
areas this effect would not be as pronounced and "usually does not occur at all".
The endoperidium is 1 to 3 cm (0.393700787401575 to 1.2 in) in diameter by 0.9 to 2 cm (0.354330708661417 to 0.78740157480315 in) high, sessile, and a dull grayish-brown. The peristome is made of radially arranged fibrils that clump together at the apex in groups of unequal length to form an opening that appears jagged or torn. The circular area bordering the peristome is a paler color. Spores are thought to be dispersed by the wind sucking them out when it blows over the hole, or when falling raindrops hit the flexible endoperidium, creating a puff of air that forces the spores through the ostiole.
Microscopic characteristics
The spore sac contains the glebaGleba
Gleba is the fleshy spore-bearing inner mass of fungi such as the puffball or stinkhorn.The gleba is a solid mass of spores, generated within an enclosed area within the sporocarp. The continuous maturity of the sporogenous cells leave the spores behind as a powdery mass that can be easily blown away...
, which is composed of a pseudocolumella, unbranched threads (the capillitium), the spore-bearing cells (basidia) and the spores
Basidiospore
A basidiospore is a reproductive spore produced by Basidiomycete fungi. Basidiospores typically each contain one haploid nucleus that is the product of meiosis, and they are produced by specialized fungal cells called basidia. In grills under a cap of one common species in the phylum of...
themselves; all of these microscopic elements have certain characteristic features that help distinguish G. triplex from other superficially similar earthstars.
The spores are spherical, and 3.5–4.5 µm
Micrometre
A micrometer , is by definition 1×10-6 of a meter .In plain English, it means one-millionth of a meter . Its unit symbol in the International System of Units is μm...
in diameter. They are covered with short narrow abruptly terminating projections of a translucent (hyaline
Hyaline
The term hyaline denotes a substance with a glass-like appearance.-Histopathology:In histopathological medical usage, a hyaline substance appears glassy and pink after being stained with haematoxylin and eosin — usually it is an acellular, proteinaceous material...
) substance, which turn a pale cinnamon brown in potassium hydroxide
Potassium hydroxide
Potassium hydroxide is an inorganic compound with the formula KOH, commonly called caustic potash.Along with sodium hydroxide , this colorless solid is a prototypical strong base. It has many industrial and niche applications. Most applications exploit its reactivity toward acids and its corrosive...
, and a dark dull brown (nearly sepia
Sepia (color)
Sepia is a dark brown-grey color, named after the rich brown pigment derived from the ink sac of the common cuttlefish Sepia.The word sepia is the Latinized form of the Greek σηπία, sēpía, cuttlefish.-Sepia in human culture:...
) when stained with iodine
Iodine
Iodine is a chemical element with the symbol I and atomic number 53. The name is pronounced , , or . The name is from the , meaning violet or purple, due to the color of elemental iodine vapor....
. The capillitium is made of what appears to be encrusted cylindrical filaments 3–6 µm in diameter, of a color varying from hyaline to dull yellowish brown in potassium hydroxide
Potassium hydroxide
Potassium hydroxide is an inorganic compound with the formula KOH, commonly called caustic potash.Along with sodium hydroxide , this colorless solid is a prototypical strong base. It has many industrial and niche applications. Most applications exploit its reactivity toward acids and its corrosive...
, and yellowish in iodine
Iodine
Iodine is a chemical element with the symbol I and atomic number 53. The name is pronounced , , or . The name is from the , meaning violet or purple, due to the color of elemental iodine vapor....
; its walls are thickened to the point where the interior (lumen
Lumen (anatomy)
A lumen in biology is the inside space of a tubular structure, such as an artery or intestine...
) appears as only a line. Either two or four spores are attached to the basidia, and the sterigmata (extensions of the basidia that attach the spores) are long, up to 20 µm. Geastrum triplex does not have cystidia.
Similar species
Geastrum triplex may be confused with G. saccatumGeastrum saccatum
Geastrum saccatum, commonly known as the rounded earthstar, is a species of mushroom belonging in the Geastrum genus. It is found in North America and Europe and is found growing on rotting wood. It is considered inedible by mushroomers, because of its bitter taste. It is a common mushroom, but...
or G. fimbriatum
Geastrum fimbriatum
Geastrum fimbriatum or Rounded Earthstar is an inedible species of mushroom belonging to the genus Geastrum, or earthstar fungi.-External links:*...
, as the rays do not always crack around the perimeter to form a bowl under the spore case. However, it is larger than either of these species. The combination of characteristics which distinguish G. triplex from other earthstars include the lack of debris adhering to the outer surfaces, the saucer-like base in which the spore case is seated, the relatively large size, the fibrillose peristome and the paler area surrounding the peristome separating it from the rest of the endoperidium. Unlike some other Geastrum species, the rays of G. triplex are not hygroscopic: they do not open and close in response to changes in humidity.
Habitat and distribution
Geastrum triplex is a saprobic fungus: it derives nutrients from decomposing organic matter. The fruit bodies are usually found growing singly or more commonly in groups in hardwood forests where much humus has accumulated; in Mexico, they have been collected in tropical deciduous forestTropical and subtropical moist broadleaf forests
Tropical and subtropical moist broadleaf forests , also known as tropical moist forests, are a tropical and subtropical forest biome....
. Fruit bodies are often found around well-rotted tree stumps; they are initially almost buried in the loose duff
Forest floor
The forest floor, also called detritus, duff and the O horizon, is one of the most distinctive features of a forest ecosystem. It mainly consists of shed vegetative parts, such as leaves, branches, bark, and stems, existing in various stages of decomposition above the soil surface...
, but emerge during maturity as the downward curling of the rays exposes the spore sac. Old fruit bodies are persistent, and may survive the winter to be found the following spring or summer. A Dutch study reported a propensity for G. triplex to grow on soil made calcium
Calcium
Calcium is the chemical element with the symbol Ca and atomic number 20. It has an atomic mass of 40.078 amu. Calcium is a soft gray alkaline earth metal, and is the fifth-most-abundant element by mass in the Earth's crust...
-rich from washed-out chalk
Chalk
Chalk is a soft, white, porous sedimentary rock, a form of limestone composed of the mineral calcite. Calcite is calcium carbonate or CaCO3. It forms under reasonably deep marine conditions from the gradual accumulation of minute calcite plates shed from micro-organisms called coccolithophores....
of crushed shells on bicycling paths. It is described as common in North America and Europe. One author states it is commonly found under beech
Beech
Beech is a genus of ten species of deciduous trees in the family Fagaceae, native to temperate Europe, Asia and North America.-Habit:...
trees.
Geastrum triplex has a widespread distribution, and has been collected in Asia (China, Korea Iran, and Turkey), Australia, Europe (Belgium, Czech Republic, Sweden, and the Canary Islands), and Africa (Congo, South Africa). In North America, its range extends north to Canada and south to Mexico, including the whole continental United States and Hawaii. In Central and South America the fungus has been reported from Panama, Trinidad and Tobago, Argentina, Brazil, and Chile.
Edibility
Although the fruit bodies of Geastrum triplex are nonpoisonous, they are tough and fibrous, and of "no alimentary interest". Mycologist David AroraDavid Arora
David Arora is an American mycologist, naturalist, and writer. He is the author of two popular books on mushroom identification, Mushrooms Demystified and All That the Rain Promises and More.......
says that they are reputed to be edible
Edible mushroom
Edible mushrooms are the fleshy and edible fruiting bodies of several species of fungi. Mushrooms belong to the macrofungi, because their fruiting structures are large enough to be seen with the naked eye. They can appear either below ground or above ground where they may be picked by hand...
when immature—when the gleba is still white and firm—but adds that they are rarely found in this form.
In traditional medicine
Earthstars were used medicinally by Native American Indians. The BlackfootBlackfoot
The Blackfoot Confederacy or Niitsítapi is the collective name of three First Nations in Alberta and one Native American tribe in Montana....
called them ka-ka-toos, meaning "fallen stars", and according to legend, they were an indication of supernatural events. The Cherokee
Cherokee
The Cherokee are a Native American people historically settled in the Southeastern United States . Linguistically, they are part of the Iroquoian language family...
put fruit bodies on the navels of babies after childbirth until the withered umbilical cord fell off, "both as a prophylactic and a therapeutic measure". In traditional Chinese medicine
Traditional Chinese medicine
Traditional Chinese Medicine refers to a broad range of medicine practices sharing common theoretical concepts which have been developed in China and are based on a tradition of more than 2,000 years, including various forms of herbal medicine, acupuncture, massage , exercise , and dietary therapy...
, G. triplex is used to reduce inflammation
Inflammation
Inflammation is part of the complex biological response of vascular tissues to harmful stimuli, such as pathogens, damaged cells, or irritants. Inflammation is a protective attempt by the organism to remove the injurious stimuli and to initiate the healing process...
in the respiratory tract, and to staunch bleeding and reduce swelling.
Chemistry
The fruit bodies of Geastrum triplex have been chemically analyzedAnalytical chemistry
Analytical chemistry is the study of the separation, identification, and quantification of the chemical components of natural and artificial materials. Qualitative analysis gives an indication of the identity of the chemical species in the sample and quantitative analysis determines the amount of...
and shown to contain a number of bioactive compounds, including fungal sterol
Sterol
Sterols, also known as steroid alcohols, are a subgroup of the steroids and an important class of organic molecules. They occur naturally in plants, animals, and fungi, with the most familiar type of animal sterol being cholesterol...
s such as ergosta-4,6,8,(14),22-tetraen-3-one,5,6-dihydroergosterol, ergosterol
Ergosterol
Ergosterol is a sterol found in fungi, and named for ergot, a common name for the members of the fungal genus Claviceps from which ergosterol was first isolated. Ergosterol does not occur in plant or animal cells...
, and peroxyergosterol. The fungus also contains various fatty acid
Fatty acid
In chemistry, especially biochemistry, a fatty acid is a carboxylic acid with a long unbranched aliphatic tail , which is either saturated or unsaturated. Most naturally occurring fatty acids have a chain of an even number of carbon atoms, from 4 to 28. Fatty acids are usually derived from...
s, notably myristic
Myristic acid
Myristic acid, also called tetradecanoic acid, is a common saturated fatty acid with the molecular formula CH312COOH. A myristate is a salt or ester of myristic acid....
, palmitic
Palmitic acid
Palmitic acid, or hexadecanoic acid in IUPAC nomenclature, is one of the most common saturated fatty acids found in animals and plants. Its molecular formula is CH314CO2H. As its name indicates, it is a major component of the oil from palm trees . Palmitate is a term for the salts and esters of...
, stearic
Stearic acid
Stearic acid is the saturated fatty acid with an 18 carbon chain and has the IUPAC name octadecanoic acid. It is a waxy solid, and its chemical formula is CH316CO2H. Its name comes from the Greek word στέαρ "stéatos", which means tallow. The salts and esters of stearic acid are called stearates...
, oleic
Oleic acid
Oleic acid is a monounsaturated omega-9 fatty acid found in various animal and vegetable fats. It has the formula CH37CH=CH7COOH. It is an odorless, colourless oil, although commercial samples may be yellowish. The trans isomer of oleic acid is called elaidic acid...
, alpha-linolenic
Alpha-linolenic acid
α-Linolenic acid is an organic compound found in many common vegetable oils. In terms of its structure, it is named all-cis-9,12,15-octadecatrienoic acid. In physiological literature, it is given the name 18:3 ....
, and linoeic acid.