Geastrum pectinatum
Encyclopedia
Geastrum pectinatum is an inedible species of mushroom
belonging to the earthstar family
of fungi. Although young specimens are spherical, fruit body
development involves the outer layer of tissue splitting open like a star into 7 to 10 pointed rays that eventually bend back to point downward, revealing a small – 1 to 2.5 cm (0.393700787401575 to 0.984251968503937 ) broad – spore
sac. The spore sac is supported by a small radially wrinkled stalk. There is a distinct conical opening (peristome) at the top of the spore sac that is up to 8 mm (0.31496062992126 in) long. It is commonly known
as the beaked earthstar or the beret earthstar, in reference to the shape of the spore sac and its prominent, protruding peristome. The mass of spores and surrounding cells within the sac, the gleba
, is dark-brown, and becomes powdery in mature specimens. Spore
s are spherical, measuring 4 to 6 micrometer
s in diameter, with warts on their surfaces. Although uncommon, Geastrum pectinatum has a cosmopolitan distribution
, and has been collected in various locations in Europe, North and South America, Asia and Africa, where it grows on the ground in open woods. Like several other earthstars, crystals of calcium oxalate
are found on G. pectinatum, and are thought to be involved in fruit body maturation.
published the first description
of Geastrum pectinatum in 1801. In 1860, Miles Joseph Berkeley
and Moses Ashley Curtis
described the species Geastrum biplicatum (originally named Geaster biplicatus), based on specimens sent to them by Charles Wright
that he obtained from the Bonin Islands during the North Pacific Exploring and Surveying Expedition
. Japanese mycologist Sanshi Imai considered this identical with G. pectinatum in a 1936 publication. In 1959, mycologist J.T. Palmer reported comparing the original specimen collected by Persoon with fresh samples of what were then thought to be the distinct species G. plicatum and G. tenuipes (named by English naturalist Miles Joseph Berkeley
in 1838 and 1848, respectively) and concluded the three specimens were synonymous; the original Persoon specimen was then designated as the neotype.
In Ponce de Leon's classification of Geastrum
, he placed the species in the subgenus
Geastrum, section Geastrum, as the type
of the subsection Sulcostomata, group Pectinatum. Other species in this group—characterized by a determinate peristome surrounded by a groove—are G. xerophilum, and G. furfuraceum. In Stanek's (1958) infrageneric concept, G. pectinatum is placed in section Perimyceliata (encompassing species whereby the mycelial layer covers the entire endoperidium), in subsection Glabrostomata, which includes species with plicate peristomes.
The specific epithet is derived from the Latin
pectinatum, "like a comb". Its common name
s include the "beaked earthstar" or the "beret earthstar". Samuel Frederick Gray
called it the "comblike shell-puff" in his 1821 "A Natural Arrangement of British Plants".
, G. pectinatum has a fruit body
wall that is multilayered. At maturity, the outer layer (the exoperidium) splits open from the top in a stellate (star-shaped) manner into 7–9 rays that support the spore sac contained within the inner wall (the endoperidium). The expanded specimens are up to 5 cm (2 in) broad and 6 cm (2.4 in) tall. The rays of the exoperidium bend back (reflex), simultaneously elevating the spore sac above the ground in what is known as the fornicate condition; this position exposes the spore sac to more air currents, aiding spore dispersal. The surface of the rays often crack to reveal lighter-colored areas, especially along the edges. Together with a well-developed layer of mycelium
, the rays are typically bound to fragments of earth or forest duff
.
The tough and membranous endoperidium comprising the spore sac, purple-brown in color and 0.5 to 1.5 cm (0.196850393700787 to 0.590551181102362 in) tall by 1 to 2.5 cm (0.393700787401575 to 0.984251968503937 ) wide, is supported by a small stalk—a pedicel—that is 3–4 mm long by 7–10 mm wide and which has a grooved (sulcate) apophysis, or swelling. This ring-shaped swelling is made of remnants from a tissue called the pseudoparenchymatous layer. When fresh, the pseudoparenchymatous layer is whitish in color, thick and fleshy; it dries to become brown to dark brown while shrinking and often splitting and peeling. The endoperidium may be pruinose—covered with fine, white, powder—although the presence of this characteristic has been noted as being somewhat variable. The spore sac is opened by a single apical pore atop a conical "beak", or peristome
. The peristome is pectinate—made of tissue that resembles the teeth of a comb; the specific epithet is named after this characteristic. The peristome is 2 to 5 mm (0.078740157480315 to 0.196850393700787 in) long, and comprises 20–32 distinct ridges. The mass of spores and surrounding cells within the sac, the gleba
, is dark-brown, and becomes powdery in mature specimens. Internally, the endoperidium contains a structure called the columella that is narrowly conical in shape, whitish or pale brown, and extends more than halfway into the gleba. G. pectinatum has no distinguishable odor or taste; like other earthstar mushrooms, it is inedible, and of "no alimentary interest".
s of G. pectinatum are brown and opaque. They have a roughly spherical shape and are ornamented with transparent (hyaline
), truncate warts; the diameter is 4–4.5 µm
, or 5.5–6.5 if the lengths of the warts is included. Spore-bearing cells, the basidia, are 2- or 4-spored, while cystidia (specialized sterile cells that occur at the hymenial
surface in some mushrooms) are absent. The capillitia—a mass of thread-like sterile fibers dispersed among the spores—are light brown and 3–7 µm in diameter. They are tapered, thick-walled with a narrow interior, and either smooth or slightly encrusted.
Geastrum pectinatum has been mistaken for the morphologically similar but smaller species G. schmidelii. The latter species lacks vertical striations on the basal portions of the endoperidium, and does not have a pseudoparenchymatous collar around the stem. Another similar species, G. berkeleyi
, has a shorter stem and is missing the ridges at the base of the spore sac. Further, the color of its spore sac is usually brown, in contrast to the gray-blue of G. pectinatum. G. xerophilum also has a dusting of white powder on the surface of the spore sac, but unlike G. pectinatum, consistently lacks a ring at the base of the pedicel; furthermore, in contrast to G. pectinatum, the spores of G. xerophilum are yellow and contain oil drops that are readily observable with a microscope. G. striatum has smaller fruit bodies than G. pectinatum, and a distinct collar-like apophysis.
. In Hawaii, it is usually found growing in duff
under coastal Casuarina
and groves of Cupressus
. The species has been noted to occur in late summer and autumn (in Britain and Europe), but the fruit bodies may dry and persist for some time.
Geastrum pectinatum has a cosmopolitan distribution
. It has been reported from Australia, and New Zealand, Africa (the Congo, South Africa) Central America (Costa Rica), Asia (Northeastern China and Japan), and South America (Brazil). In Europe, it has been reported from Belgium, Ireland, Germany, the Netherlands, Norway, and Sweden. In the Middle East, it has been recorded in Israel, and Turkey. In North America, it is known from the United States (including Hawaii), Canada, and Mexico. It is in the Red Data Book
(documenting rare and endangered species) of Latvia, and is considered a threatened species
in Poland. North American sources gives its frequency of appearance as "rare", but Stellan Sunhede, in his 1989 monograph
on the Geastraceae, considers it one of the most common earthstar mushrooms of northern Europe.
is a common crystalline compound found in many fungi, including the earthstars. The presence of calcium oxalate crystals—apparent as a whitish powder on the surface of the spore sac—has been verified for G. pectinatum using scanning electron microscopy. The calcium oxalate crystals occur in the tetragonal form, known as weddellite
. A study on the related species Geastrum saccatum
has shown that these crystals are responsible for the characteristic opening (dehiscence
) of the outer peridial layers. The formation of calcium oxalate crystals stretches the layers of the outer walls, pushing apart the inner and outer layers of the peridium.
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...
belonging to the earthstar family
Geastraceae
The earthstars are the family Geastraceae of gasterocarpic basidiomycetes . It includes the genera Geastrum and Myriostoma. About sixty-four species are classified in this family, divided among eight genera....
of fungi. Although young specimens are spherical, 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...
development involves the outer layer of tissue splitting open like a star into 7 to 10 pointed rays that eventually bend back to point downward, revealing a small – 1 to 2.5 cm (0.393700787401575 to 0.984251968503937 ) broad – 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 is supported by a small radially wrinkled stalk. There is a distinct conical opening (peristome) at the top of the spore sac that is up to 8 mm (0.31496062992126 in) long. It is commonly known
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...
as the beaked earthstar or the beret earthstar, in reference to the shape of the spore sac and its prominent, protruding peristome. The mass of spores and surrounding cells within the sac, 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...
, is dark-brown, and becomes powdery in mature specimens. 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 are spherical, measuring 4 to 6 micrometer
Micrometer
A micrometer , sometimes known as a micrometer screw gauge, is a device incorporating a calibrated screw used widely for precise measurement of small distances in mechanical engineering and machining as well as most mechanical trades, along with other metrological instruments such as dial, vernier,...
s in diameter, with warts on their surfaces. Although uncommon, Geastrum pectinatum has a cosmopolitan distribution
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...
, and has been collected in various locations in Europe, North and South America, Asia and Africa, where it grows on the ground in open woods. Like several other earthstars, crystals of calcium oxalate
Calcium oxalate
Calcium oxalate is a chemical compound that forms needle-shaped crystals, known in plants as raphides. A major constituent of human kidney stones, the chemical is also found in beerstone, a scale that forms on containers used in breweries...
are found on G. pectinatum, and are thought to be involved in fruit body maturation.
Taxonomy, classification, and naming
Christian Hendrik PersoonChristian Hendrik Persoon
Christiaan Hendrik Persoon was a mycologist who made additions to Linnaeus' mushroom taxonomy.-Early life:...
published the first description
Species description
A species description or type description is a formal description of a newly discovered species, usually in the form of a scientific paper. Its purpose is to give a clear description of a new species of organism and explain how it differs from species which have been described previously, or are...
of Geastrum pectinatum in 1801. In 1860, Miles Joseph Berkeley
Miles Joseph Berkeley
Miles Joseph Berkeley was an English cryptogamist and clergyman, and one of the founders of the science of plant pathology....
and Moses Ashley Curtis
Moses Ashley Curtis
Moses Ashley Curtis was a noted American botanist.Curtis was born in Stockbridge, Massachusetts and educated at Williams College in Massachusetts. After graduating, he became a tutor for the children of former Governor Edward Bishop Dudley in Wilmington, North Carolina, returning to Massachusetts...
described the species Geastrum biplicatum (originally named Geaster biplicatus), based on specimens sent to them by Charles Wright
Charles Wright (botanist)
Charles Wright was an American botanist.Wright was born in Wethersfield, Connecticut, the son of James Wright and Mary née Goodrich. He studied classics and mathematics at Yale, and in October 1835 moved to Natchez, Mississippi to tutor a plantation owner's family...
that he obtained from the Bonin Islands during the North Pacific Exploring and Surveying Expedition
North Pacific Exploring and Surveying Expedition
The North Pacific Exploring and Surveying Expedition, also known as the Rodgers-Ringgold Expedition was a United States scientific and exploring project from 1853 to 1856....
. Japanese mycologist Sanshi Imai considered this identical with G. pectinatum in a 1936 publication. In 1959, mycologist J.T. Palmer reported comparing the original specimen collected by Persoon with fresh samples of what were then thought to be the distinct species G. plicatum and G. tenuipes (named by English naturalist Miles Joseph Berkeley
Miles Joseph Berkeley
Miles Joseph Berkeley was an English cryptogamist and clergyman, and one of the founders of the science of plant pathology....
in 1838 and 1848, respectively) and concluded the three specimens were synonymous; the original Persoon specimen was then designated as the neotype.
In Ponce de Leon's classification of 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....
, he placed the species in the subgenus
Subgenus
In biology, a subgenus is a taxonomic rank directly below genus.In zoology, a subgeneric name can be used independently or included in a species name, in parentheses, placed between the generic name and the specific epithet: e.g. the Tiger Cowry of the Indo-Pacific, Cypraea tigris Linnaeus, which...
Geastrum, section Geastrum, as the type
Type species
In biological nomenclature, a type species is both a concept and a practical system which is used in the classification and nomenclature of animals and plants. The value of a "type species" lies in the fact that it makes clear what is meant by a particular genus name. A type species is the species...
of the subsection Sulcostomata, group Pectinatum. Other species in this group—characterized by a determinate peristome surrounded by a groove—are G. xerophilum, and G. furfuraceum. In Stanek's (1958) infrageneric concept, G. pectinatum is placed in section Perimyceliata (encompassing species whereby the mycelial layer covers the entire endoperidium), in subsection Glabrostomata, which includes species with plicate peristomes.
The specific epithet is derived from the Latin
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...
pectinatum, "like a comb". Its common name
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...
s include the "beaked earthstar" or the "beret earthstar". Samuel Frederick Gray
Samuel Frederick Gray
Samuel Frederick Gray was a British botanist, mycologist, and pharmacologist. He was the father of the zoologists John Edward Gray and George Robert Gray.-Background:...
called it the "comblike shell-puff" in his 1821 "A Natural Arrangement of British Plants".
Description
Immature specimens – 1 to 2 cm (0.393700787401575 to 0.78740157480315 in) diameter – are roughly spherical and begin their development submerged in the ground, but gradually push above ground during maturation. In this state the outer surface is covered with mycelia, which forms a soft, fluffy coat that holds soil and debris to the outer surface. The young fruit bodies often have a rounded knob or protuberance. Like other members of genus GeastrumGeastrum
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....
, G. pectinatum has a 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...
wall that is multilayered. At maturity, the outer layer (the exoperidium) splits open from the top in a stellate (star-shaped) manner into 7–9 rays that support the spore sac contained within the inner wall (the endoperidium). The expanded specimens are up to 5 cm (2 in) broad and 6 cm (2.4 in) tall. The rays of the exoperidium bend back (reflex), simultaneously elevating the spore sac above the ground in what is known as the fornicate condition; this position exposes the spore sac to more air currents, aiding spore dispersal. The surface of the rays often crack to reveal lighter-colored areas, especially along the edges. Together with a well-developed layer of 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...
, the rays are typically bound to fragments of earth or forest 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...
.
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...
. The peristome is pectinate—made of tissue that resembles the teeth of a comb; the specific epithet is named after this characteristic. The peristome is 2 to 5 mm (0.078740157480315 to 0.196850393700787 in) long, and comprises 20–32 distinct ridges. The mass of spores and surrounding cells within the sac, 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...
, is dark-brown, and becomes powdery in mature specimens. Internally, the endoperidium contains a structure called the columella that is narrowly conical in shape, whitish or pale brown, and extends more than halfway into the gleba. G. pectinatum has no distinguishable odor or taste; like other earthstar mushrooms, it is inedible, and of "no alimentary interest".
Microscopic characteristics
The sporeSpore
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 of G. pectinatum are brown and opaque. They have a roughly spherical shape and are ornamented with transparent (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...
), truncate warts; the diameter is 4–4.5 µm
Micrometer
A micrometer , sometimes known as a micrometer screw gauge, is a device incorporating a calibrated screw used widely for precise measurement of small distances in mechanical engineering and machining as well as most mechanical trades, along with other metrological instruments such as dial, vernier,...
, or 5.5–6.5 if the lengths of the warts is included. Spore-bearing cells, the basidia, are 2- or 4-spored, while cystidia (specialized sterile cells that occur at the hymenial
Hymenium
The hymenium is the tissue layer on the hymenophore of a fungal fruiting body where the cells develop into basidia or asci, which produce spores. In some species all of the cells of the hymenium develop into basidia or asci, while in others some cells develop into sterile cells called cystidia or...
surface in some mushrooms) are absent. The capillitia—a mass of thread-like sterile fibers dispersed among the spores—are light brown and 3–7 µm in diameter. They are tapered, thick-walled with a narrow interior, and either smooth or slightly encrusted.
Similar species
Geastrum berkeleyi
Geastrum berkeleyi is an inedible species of mushroom belonging to the genus Geastrum, or earthstar fungi.-External links:*...
, has a shorter stem and is missing the ridges at the base of the spore sac. Further, the color of its spore sac is usually brown, in contrast to the gray-blue of G. pectinatum. G. xerophilum also has a dusting of white powder on the surface of the spore sac, but unlike G. pectinatum, consistently lacks a ring at the base of the pedicel; furthermore, in contrast to G. pectinatum, the spores of G. xerophilum are yellow and contain oil drops that are readily observable with a microscope. G. striatum has smaller fruit bodies than G. pectinatum, and a distinct collar-like apophysis.
Distribution and habitat
This species has been reported to grow solitary or in groups on sandy soil or rich composted soil in both mixed and coniferous forests, often beneath cedarsCedar wood
Cedar wood comes from several different trees that grow in different parts of the world, and may have different uses.* California incense-cedar, from Calocedrus decurrens, is the primary type of wood used for making pencils...
. In Hawaii, it is usually found growing in 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...
under coastal Casuarina
Casuarina
Casuarina is a genus of 17 species in the family Casuarinaceae, native to Australasia, southeast Asia, and islands of the western Pacific Ocean. It was once treated as the sole genus in the family, but has been split into three genera .They are evergreen shrubs and trees growing to 35 m tall...
and groves of Cupressus
Cupressus
The genus Cupressus is one of several genera within the family Cupressaceae that have the common name cypress; for the others, see cypress. It is considered a polyphyletic group...
. The species has been noted to occur in late summer and autumn (in Britain and Europe), but the fruit bodies may dry and persist for some time.
Geastrum pectinatum has a cosmopolitan distribution
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...
. It has been reported from Australia, and New Zealand, Africa (the Congo, South Africa) Central America (Costa Rica), Asia (Northeastern China and Japan), and South America (Brazil). In Europe, it has been reported from Belgium, Ireland, Germany, the Netherlands, Norway, and Sweden. In the Middle East, it has been recorded in Israel, and Turkey. In North America, it is known from the United States (including Hawaii), Canada, and Mexico. It is in the Red Data Book
Regional Red List
A Regional Red List is a report of the threatened status of species within a certain country or region. It is based on the IUCN Red List of Threatened Species, an inventory of the conservation status of species on a global scale...
(documenting rare and endangered species) of Latvia, and is considered a threatened species
Threatened species
Threatened species are any speciesg animals, plants, fungi, etc.) which are vulnerable to endangerment in the near future.The World Conservation Union is the foremost authority on threatened species, and treats threatened species not as a single category, but as a group of three categories,...
in Poland. North American sources gives its frequency of appearance as "rare", but Stellan Sunhede, in his 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...
on the Geastraceae, considers it one of the most common earthstar mushrooms of northern Europe.
Calcium oxalate crystals
Calcium oxalateCalcium oxalate
Calcium oxalate is a chemical compound that forms needle-shaped crystals, known in plants as raphides. A major constituent of human kidney stones, the chemical is also found in beerstone, a scale that forms on containers used in breweries...
is a common crystalline compound found in many fungi, including the earthstars. The presence of calcium oxalate crystals—apparent as a whitish powder on the surface of the spore sac—has been verified for G. pectinatum using scanning electron microscopy. The calcium oxalate crystals occur in the tetragonal form, known as weddellite
Weddellite
Weddellite is a mineral form of calcium oxalate named for occurrences of millimeter-sized crystals found in bottom sediments of the Weddell Sea, off Antarctica...
. A study on the related species 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...
has shown that these crystals are responsible for the characteristic opening (dehiscence
Dehiscence (botany)
Dehiscence is the opening, at maturity, in a pre-defined way, of a plant structure, such as a fruit, anther, or sporangium, to release its contents. Sometimes this involves the complete detachment of a part. Structures that open in this way are said to be dehiscent...
) of the outer peridial layers. The formation of calcium oxalate crystals stretches the layers of the outer walls, pushing apart the inner and outer layers of the peridium.
External links
- botany.cz Geastrum pectinatum Pers. – hvězdovka dlouhokrká / hviezdovka dlhokŕčková (in Czech)