Chorioactis geaster
Encyclopedia
Chorioactis is a genus
of fungus
that contains the single species Chorioactis geaster; the mushroom is commonly
known as the devil’s cigar or the Texas star in the United States, while in Japan it is called .
This extremely rare mushroom is notable for its unusual appearance and disjunct distribution
: it is only found only in select locales in Texas
and Japan
. The fruit body
, which grows on the stumps or dead roots of cedar elms (in Texas) or dead oak
s (in Japan), somewhat resembles a dark brown or black cigar before it splits open radially into a starlike arrangement of four to seven leathery rays. The interior surface of the fruit body bears the spore
-bearing tissue known as the hymenium
, and is colored white to brown, depending on its age. Fruit body opening can be accompanied by a distinct hissing sound and the release of a smoky cloud of spore
s.
Fruit bodies were first collected in Austin, Texas
, and the species was named Urnula geaster in 1893; it was later found in Kyushu
in 1937, but the mushroom was not reported again in Japan until 1973. Although the new genus Chorioactis was proposed to accommodate the unique species a few years after its original discovery, it was not until 1968 that it was accepted as a valid genus. Its classification
has also been a source of confusion. Historically, Chorioactis was placed in the Sarcosomataceae
family of fungi, despite inconsistencies in the microscopic structure of the ascus
, the saclike structure in which spores are formed. Phylogenetic analyses of the past decade have clarified the fungus's classification: Chorioactis, along with three other genera, make up the Chorioactidaceae
family, a grouping of related fungi formally acknowledged in 2008. In 2009, Japanese researchers reported discovering a form of the fungus missing the sexual stage of its life cycle
; this asexual state
was named Kumanasamuha geaster.
in 1893 by botanist Lucien Marcus Underwood
, who sent the specimens to mycologist Charles Horton Peck
for identification. Peck described the species as Urnula geaster in that year's Annual Report of the New York State botanist, although he expressed doubt about its generic
placement in Urnula
. In 1902, student mycologist Elsie Kupfer questioned the proposed classification
of various species in the genera Urnula and Geopyxis
, as suggested in an 1896 publication on the Discomycetes
by German mycologist Heinrich Rehm
. She considered Rehm's transfer of the species to the genus Geopyxis illogical:
(the fertile, spore-bearing tissue) of the Texan species with a number of similar ones—Geopyxis carbonaria
, Urnula craterium
, and Urnula terrestris (now known as Podophacidium xanthomelum
). She concluded that the Texan species was so dissimilar as to warrant its own genus, which she named Chorioactis. Although this taxonomical
change was opposed in later studies of the fungus by Frederick De Forest Heald and Frederick Adolf Wolf (1910) and Fred Jay Seaver
(1928, 1942), Chorioactis was established as a valid genus in 1968 by Finn-Egil Eckblad
in his comprehensive monograph
about the Discomycetes.
family. A 1983 monograph
on the family included Chorioactis in the tribe
Sarcosomateae (along with the genera Desmazierella
, Sarcosoma
, Korfiella
, Plectania
, and Urnula
), a grouping of fungi characterized by having spores lacking small wartlike projections (verruculae) capable of absorbing blue dye. A 1994 study of the structural features of the asci
and the ascospore
s concluded that Chorioactis was more closely aligned with the Sarcoscyphaceae
, although it conceded that the layering of the cells comprising the walls of the ascus differed considerably from the other members of the family. It was not until 1999 that the results of phylogenetic analysis firmly challenged the traditional classification, showing C. geaster to be part of a distinct lineage, or clade
, that includes species in the genera Desmazierella
, Neournula
, and Wolfina
, taxa that were distributed among both families. This analysis was later corroborated when it was shown that the grouping of these four genera (by then called the "Chorioactis clade") represented a sister clade
to the Sarcosomataceae, and a new family, the Chorioactidaceae
, was erected to contain them. Although C. geaster shares some characteristics with the other Chorioactidaceae genera, including dark-colored superficial "hairs" on the outer surface of the fruit bodies, it is distinguished from them by its tan- to orange- (rather than black) hymenia
.
The specific epithet geaster alludes to its superficial resemblance to members of genus Geastrum
, which also open to form star-shaped fruit bodies commonly called "earthstars". In the United States, Chorioactis geaster is commonly
known as the Texas star, or the devil's cigar. Regarding the origin of the latter name American mycologist Fred Jay Seaver commented: "Whether the name Devil's Cigar refers to the form of the young specimens which resemble a bloated cigar in form, as well as in color, or to the fact that the fungus appears to "smoke" at maturity, we cannot say ... At any rate, the name is very appropriate." In 1997, Texan state Senator Chris Harris filed a bill
to make C. geaster the official state fungus of Texas. The bill passed the Senate
but did not succeed in the House
. In Japan the mushroom is called kirinomitake (キリノミタケ), because the immature, unopened fruit body bears some resemblance to the seed pods of kiri, the Empress tree (Paulownia tomentosa
).
. The stem, which is usually buried in the ground, is shorter than the hollow fruit body or equals it in length, although the stem length is somewhat variable depending on the depth of the underground root to which it is attached. The flesh
of the stem and the wall of the fruit body is white, while the inner surface is yellowish-white, turning light brown with age. The fruit body varies in width from 1.2 to 3.5 cm (0.47244094488189 to 1.4 in) in the thickest portion, and has a length of 4 to 12 cm (1.6 to 4.7 ); the stem is 0.75 to 1.5 cm (0.295275590551181 to 0.590551181102362 in) wide by 1 to 5 cm (0.393700787401575 to 2 in) long. Both stem and fruit body are covered by a dense layer of soft brown velvety "hairs", or tomentum. In maturity, the fruit body splits open into 4–7 rays that curve downward, similar to mushrooms of the genus Geastrum
. The spores are borne on the inner surface of the rays, which, depending on the maturity of the specimen, may range in color from whitish to saffron
to salmon
to butterscotch to chestnut
. The leathery rays are up to 0.35 cm (0.137795275590551 in) thick.
The fruit body remains closed until shortly before spore discharge; dehiscence
(fruit body opening) is caused by the pressure exerted by swollen paraphyses
—sterile (i.e., non-reproductive) cells that are interspersed between the ascospore
s. Dehiscence is accompanied by the release of clouds of spores resembling dust; the characteristic shape of the unopened fruit body, as well as the smoky spore release give the fungus its common name "Devil's cigar". The spore puffing upon rupture is thought to be caused by the sudden change in relative humidity between the interior chamber of the fruit body and the outside environment. Dehiscence is accompanied by a hissing sound, an auditory phenomenon known to occur in about fifteen other fungal species.
are oblong to spindle-shaped, and are flattened on one side; they have dimensions of 54–68 µm
by 10–13 µm. The spores each contain 3–5 oil drops. Although the spores have been described as smooth in older literature, when viewed with transmission electron microscopy
, they are seen to have minute spots or punctures. The spores develop simultaneously (synchronously) within the ascus
, a developmental feature shared with the Sarcoscyphaceae
genera Cookeina
and Microstoma. Like other members of the Pezizales
order, the asci
of C. geaster have an operculum
—a "lid"—that opens when the spores are discharged. However, the operculum of C. geaster develops a two-layered ring zone upon dehiscence, making it structurally distinct from members of both the Sarcosomataceae
and the Sarcoscyphaceae
families.
Similar to other Discomycetes, the fruit body consists of three distinct layers of tissue: the hymenium
, the hypothecium, and the excipulum. The spore-bearing hymenium, the outermost layer of cells, contains asci interspersed with sterile cells called paraphyses
. In C. geaster, the club-shaped asci are 700–800 µm long and 14–17.25 µm thick; they are abruptly constricted at the base to a narrow pedicel. The paraphyses are initially filamentous or thread-like (filiform) but swell with age to resemble a string of beads (monoliform). The swelling of the paraphyses is believed to cause the expansion of the hymenium and subsequent splitting of the fruit body into rays; this development places the asci into an optimal position for spore release and dispersal. Supporting the cells of the hymenium is a thin layer of tightly interwoven hypha
e called the hypothecium, and underneath this is a thick layer of loosely-interwoven hyphae known as the exipulum. This tissue layer, analogous to parenchyma found in plants, gives the tissue a fibrous texture. The exipulum layer averages 34 µm in diameter, while the hypothecium is 10–14 µm. When viewed with electron microscopy
, the dark brown "hairs" on the surface of the fruit body can be seen to be adorned with conical warts or spines.
are those that seem to lack a sexual stage in their life cycle
, and typically reproduce by the process of mitosis
in structures called conidia
. In some cases, the sexual stage—or teleomorph
stage—is later identified, and a teleomorph-anamorph relationship is established between the species. The International Code of Botanical Nomenclature permits the recognition of two (or more) names for one and the same organisms, one based on the teleomorph, the other(s) restricted to the anamorph. In 2004, researchers reported a connection between C. geaster and the appearance of blackish-brown tufted structures on rotting wood. By comparing the internal transcribed spacer
region of the nuclear ribosomal DNA
from the two organisms, they established a phylogenetic
connection between Chorioactis and the fungus they called Conoplea
aff. elegantula. However, they were unable to induce the new organism to grow on artificial media, and did not definitively establish a teleomorph-anamorph connection between the fungi. In 2009, Japanese researchers found a similar fungus growing on rotting logs that were normally associated with the growth of C. geaster; they were able to grow the organism in axenic cultures
from single-spore isolates of C. geaster. They named the anamorph Kumanasamuha geaster due to its morphological
similarity with species in the genus Kumanasamuha.
, and has only been collected from Texas
and Japan
. The first reported collection in Japan was in Kyushu
in 1937, and then it was not collected again in that location until thirty-six years later. In 2006, it was observed in a humid forest near Kawakami
, Nara Prefecture
. The fungus's natural habitat in Japan is disappearing because of the practice of deforestation
and replanting with Japanese cedar (Cryptomeria japonica
). This rare mushroom has been put on the list of threatened species
in Japan. In Texas, the fungus has been reported in Collin County
, Hays
, Travis
, Dallas, Denton
, Guadalupe
, Tarrant
and Hunt
Counties. Travis, Hays, and Guadalupe counties are in central Texas, while the remainder are clustered together in the northeastern part of the state. Although the species is considered rare due to its globally restricted distribution, it may be locally abundant.
Although it is not known definitively, Chorioactis is believed to be saprobic
, deriving nutrients from decomposing organic matter. In Texas, fruit bodies are found growing singly or in groups from roots, stumps, and dead roots of cedar elm trees (Ulmus crassifolia) or Symplocos myrtacea
; in Japan, the usual host is dead oak trees
. Fruit bodies can be clustered together close to the base of the stump, or from the roots away from the stump; the stem
of the fruit body tends to originate from a point 5 to 10 cm (2 to 3.9 in) below the ground. In Texas, fruit bodies usually appear between October and April, as this period is associated with somewhat cooler weather, and the temperature and moisture conditions during this time seem to be more favorable for growth.
Scientists do not know why the fungus mysteriously lives only in Texas and Japan, locations of approximately the same latitude
, but separated by 11000 km (6,835.1 mi). Fred Jay Seaver commented "this is only another illustration of the unusual and unpredictable distribution of many species of the fungi. It would be difficult indeed to account for it, and we merely accept the facts as they are." In 2004, a research study compared the DNA sequences of both populations and used a combination of molecular phylogenetics and molecular clock
calculations to estimate the extent of genetic divergence. It concluded that the two populations have been separated for at least nineteen million years, ruling out the possibility of human introduction of the species from one location to the other. Although there are no consistent differences in morphology
between the two populations, there are several differences in their life histories
. The preferred host of Texan populations is typically roots and stumps of Ulmus crassifola, while the Japanese populations tend to grow on the fallen trunks of Symplocos myrtaceae and Quercus gilva. Texan species grow in areas subjected to periodic flooding, unlike their Japanese counterparts. Finally, only Japanese specimens can be grown in culture—the spores of Texan material have not been successfully germinated on artificial media
.
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...
of fungus
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...
that contains the single species Chorioactis geaster; the mushroom is commonly
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...
known as the devil’s cigar or the Texas star in the United States, while in Japan it is called .
This extremely rare mushroom is notable for its unusual appearance and disjunct distribution
Disjunct distribution
In biology, a taxon with a disjunct distribution is one that has two or more groups that are related but widely separated from each other geographically...
: it is only found only in select locales in Texas
Texas
Texas is the second largest U.S. state by both area and population, and the largest state by area in the contiguous United States.The name, based on the Caddo word "Tejas" meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in...
and Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
. The fruit body
Sporocarp (fungi)
In fungi, the sporocarp is a multicellular structure on which spore-producing structures, such as basidia or asci, are borne...
, which grows on the stumps or dead roots of cedar elms (in Texas) or dead oak
Oak
An oak is a tree or shrub in the genus Quercus , of which about 600 species exist. "Oak" may also appear in the names of species in related genera, notably Lithocarpus...
s (in Japan), somewhat resembles a dark brown or black cigar before it splits open radially into a starlike arrangement of four to seven leathery rays. The interior surface of the fruit body bears the 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...
-bearing tissue known as the hymenium
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...
, and is colored white to brown, depending on its age. Fruit body opening can be accompanied by a distinct hissing sound and the release of a smoky cloud of 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.
Fruit bodies were first collected in Austin, Texas
Austin, Texas
Austin is the capital city of the U.S. state of :Texas and the seat of Travis County. Located in Central Texas on the eastern edge of the American Southwest, it is the fourth-largest city in Texas and the 14th most populous city in the United States. It was the third-fastest-growing large city in...
, and the species was named Urnula geaster in 1893; it was later found in Kyushu
Kyushu
is the third largest island of Japan and most southwesterly of its four main islands. Its alternate ancient names include , , and . The historical regional name is referred to Kyushu and its surrounding islands....
in 1937, but the mushroom was not reported again in Japan until 1973. Although the new genus Chorioactis was proposed to accommodate the unique species a few years after its original discovery, it was not until 1968 that it was accepted as a valid genus. Its classification
Biological classification
Biological classification, or scientific classification in biology, is a method to group and categorize organisms by biological type, such as genus or species. Biological classification is part of scientific taxonomy....
has also been a source of confusion. Historically, Chorioactis was placed in the Sarcosomataceae
Sarcosomataceae
The Sarcosomataceae are a family of fungi in the order Pezizales. According to a 2008 estimate, the family contains 10 genera and 57 species. Most species are found in temperate areas, and are typically saprobic on rotten or buried wood....
family of fungi, despite inconsistencies in the microscopic structure of the ascus
Ascus
An ascus is the sexual spore-bearing cell produced in ascomycete fungi. On average, asci normally contain eight ascospores, produced by a meiotic cell division followed, in most species, by a mitotic cell division. However, asci in some genera or species can number one , two, four, or multiples...
, the saclike structure in which spores are formed. Phylogenetic analyses of the past decade have clarified the fungus's classification: Chorioactis, along with three other genera, make up the Chorioactidaceae
Chorioactidaceae
The Chorioactidaceae are a family of cup fungi in the Pezizales order containing four genera and six species....
family, a grouping of related fungi formally acknowledged in 2008. In 2009, Japanese researchers reported discovering a form of the fungus missing the sexual stage of its life cycle
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...
; this asexual state
Teleomorph, anamorph and holomorph
The terms teleomorph, anamorph, and holomorph apply to portions of the life cycles of fungi in the phyla Ascomycota and Basidiomycota.*Teleomorph: the sexual reproductive stage , typically a fruiting body....
was named Kumanasamuha geaster.
History
The fungus was first collected in Austin, TexasAustin, Texas
Austin is the capital city of the U.S. state of :Texas and the seat of Travis County. Located in Central Texas on the eastern edge of the American Southwest, it is the fourth-largest city in Texas and the 14th most populous city in the United States. It was the third-fastest-growing large city in...
in 1893 by botanist Lucien Marcus Underwood
Lucien Marcus Underwood
Lucien Marcus Underwood was an American botanist and mycologist of the 19th and early 20th centuries.-Biography:He was born in New Woodstock, New York, and graduated from Syracuse University...
, who sent the specimens to mycologist Charles Horton Peck
Charles Horton Peck
Charles Horton Peck, born March 30, 1833 in Sand Lake, New York, died 1917 in Albany, New York, was an American mycologist of the 19th and early 20th centuries...
for identification. Peck described the species as Urnula geaster in that year's Annual Report of the New York State botanist, although he expressed doubt about its generic
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...
placement in Urnula
Urnula
Urnula is a genus of fungi in the family Sarcosomataceae, circumscribed by Elias Magnus Fries in 1849. The genus contains six species found in Europe and North America....
. In 1902, student mycologist Elsie Kupfer questioned the proposed classification
Biological classification
Biological classification, or scientific classification in biology, is a method to group and categorize organisms by biological type, such as genus or species. Biological classification is part of scientific taxonomy....
of various species in the genera Urnula and Geopyxis
Geopyxis
Geopyxis is a genus of fungi in the family Pyronemataceae. The genus has a widespread distribution and contains seven species....
, as suggested in an 1896 publication on the Discomycetes
Discomycetes
Discomycetes is a former taxonomic class of Ascomycete fungi which contains all of the cup, sponge, brain, and some club-like fungi. It includes typical cup fungi like the scarlet elf cup and the orange peel fungus, and fungi with fruiting bodies of more unusual shape, such as morels, truffles and...
by German mycologist Heinrich Rehm
Heinrich Rehm
Heinrich Simon Ludwig Friedrich Felix Rehm was a German mycologist and lichenologist.-Publications:*Rehm, H. 1874. Ascomyceten Fasc. 5: 201-250*----. 1875. Ascomyceten 6: 251-300...
. She considered Rehm's transfer of the species to the genus Geopyxis illogical:
"Even externally the fungus does not closely answer Rehm's own description of the genus Geopyxis under which he places it; the texture of the apothecium is described as fleshy, the stem, as short and sometimes thin; while in this plant, the leathery character of the cup and the length and thickness of the stem are its noticeable features."Working with Underwood's guidance, Kupfer compared the microscopic structure of the hymenium
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...
(the fertile, spore-bearing tissue) of the Texan species with a number of similar ones—Geopyxis carbonaria
Geopyxis carbonaria
Geopyxis carbonaria, commonly known as the charcoal loving elf-cup, is a species of fungi in the genus Geopyxis, family Pyronemataceae...
, Urnula craterium
Urnula craterium
Urnula craterium is a species of cup fungus in the family Sarcosomataceae. It is parasitic on oak and various other hardwood species; it is also saprobic, as the fruit bodies develop on dead wood after it has fallen to the ground...
, and Urnula terrestris (now known as Podophacidium xanthomelum
Podophacidium
Podophacidium is a genus of fungi in the Dermateaceae family that contains two species found in Europe and North America. The type species, originally called Podophacidium terrestre Niessl, is currently known as Podophacidium xanthomelum....
). She concluded that the Texan species was so dissimilar as to warrant its own genus, which she named Chorioactis. Although this taxonomical
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...
change was opposed in later studies of the fungus by Frederick De Forest Heald and Frederick Adolf Wolf (1910) and Fred Jay Seaver
Fred Jay Seaver
Fred Jay Seaver was an American mycologist. He worked at the New York Botanical Garden for 40 years, initially as the Director of Laboratories , then as the Curator , and finally as Head Curator . He was also an editor of the journal Mycologia between 1909 and 1947.- References :...
(1928, 1942), Chorioactis was established as a valid genus in 1968 by Finn-Egil Eckblad
Finn-Egil Eckblad
Finn-Egil Eckblad was a Norwegian mycologist.He took the Dr.philos. degree in 1968, was hired as a lecturer at the University of Bergen in 1971 and as a professor at the University of Oslo in 1979. He retired in 1990....
in his comprehensive 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...
about the Discomycetes.
Classification and naming
Historically, Chorioactis was considered to be in the SarcosomataceaeSarcosomataceae
The Sarcosomataceae are a family of fungi in the order Pezizales. According to a 2008 estimate, the family contains 10 genera and 57 species. Most species are found in temperate areas, and are typically saprobic on rotten or buried wood....
family. A 1983 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 family included Chorioactis in the tribe
Tribe (biology)
In biology, a tribe is a taxonomic rank between family and genus. It is sometimes subdivided into subtribes.Some examples include the tribes: Canini, Acalypheae, Hominini, Bombini, and Antidesmeae.-See also:* Biological classification* Rank...
Sarcosomateae (along with the genera Desmazierella
Desmazierella
Desmazierella is a genus of fungi in the Sarcoscyphaceae family. There are two species in the genus, found in Europe.-External links:* at Index Fungorum...
, Sarcosoma
Sarcosoma
Sarcosoma is a genus of fungi in the family Sarcosomataceae. The genus, widespread in north temperate and tropical areas, contains five species. The anamorph form is the genus Verticicladium....
, Korfiella
Korfiella
Korfiella is a genus of fungi in the family Sarcosomataceae. A monotypic genus, it contains the single species Korfiella karnika.-External links:*...
, Plectania
Plectania
Plectania is a genus of fungi in the Sarcosomataceae family. There are 15 species in the genus, which have a widespread distribution, especially in northern temperate areas.-External links:* at Index Fungorum...
, and Urnula
Urnula
Urnula is a genus of fungi in the family Sarcosomataceae, circumscribed by Elias Magnus Fries in 1849. The genus contains six species found in Europe and North America....
), a grouping of fungi characterized by having spores lacking small wartlike projections (verruculae) capable of absorbing blue dye. A 1994 study of the structural features of the asci
Ascus
An ascus is the sexual spore-bearing cell produced in ascomycete fungi. On average, asci normally contain eight ascospores, produced by a meiotic cell division followed, in most species, by a mitotic cell division. However, asci in some genera or species can number one , two, four, or multiples...
and the ascospore
Ascospore
An ascospore is a spore contained in an ascus or that was produced inside an ascus. This kind of spore is specific to fungi classified as ascomycetes ....
s concluded that Chorioactis was more closely aligned with the Sarcoscyphaceae
Sarcoscyphaceae
The Sarcoscyphaceae are a family of cup fungi in the Pezizales order. There are 13 genera and 102 species in the family. Members of this family are cosmopolitan in distribution, being found in both tropical and temperate regions.-External links:...
, although it conceded that the layering of the cells comprising the walls of the ascus differed considerably from the other members of the family. It was not until 1999 that the results of phylogenetic analysis firmly challenged the traditional classification, showing C. geaster to be part of a distinct lineage, or clade
Clade
A clade is a group consisting of a species and all its descendants. In the terms of biological systematics, a clade is a single "branch" on the "tree of life". The idea that such a "natural group" of organisms should be grouped together and given a taxonomic name is central to biological...
, that includes species in the genera Desmazierella
Desmazierella
Desmazierella is a genus of fungi in the Sarcoscyphaceae family. There are two species in the genus, found in Europe.-External links:* at Index Fungorum...
, Neournula
Neournula
Neournula is a genus of fungi in the Chorioactidaceae family. There are two species in the genus, found in the USA, Europe, and northern Africa.-External links:* at Index Fungorum...
, and Wolfina
Wolfina
Wolfina is a genus of fungi in the Chorioactidaceae family. There are three species in the genus, found in the USA and China....
, taxa that were distributed among both families. This analysis was later corroborated when it was shown that the grouping of these four genera (by then called the "Chorioactis clade") represented a sister clade
Cladistics
Cladistics is a method of classifying species of organisms into groups called clades, which consist of an ancestor organism and all its descendants . For example, birds, dinosaurs, crocodiles, and all descendants of their most recent common ancestor form a clade...
to the Sarcosomataceae, and a new family, the Chorioactidaceae
Chorioactidaceae
The Chorioactidaceae are a family of cup fungi in the Pezizales order containing four genera and six species....
, was erected to contain them. Although C. geaster shares some characteristics with the other Chorioactidaceae genera, including dark-colored superficial "hairs" on the outer surface of the fruit bodies, it is distinguished from them by its tan- to orange- (rather than black) hymenia
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...
.
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....
, which also open to form star-shaped fruit bodies commonly called "earthstars". In the United States, Chorioactis geaster is commonly
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...
known as the Texas star, or the devil's cigar. Regarding the origin of the latter name American mycologist Fred Jay Seaver commented: "Whether the name Devil's Cigar refers to the form of the young specimens which resemble a bloated cigar in form, as well as in color, or to the fact that the fungus appears to "smoke" at maturity, we cannot say ... At any rate, the name is very appropriate." In 1997, Texan state Senator Chris Harris filed a bill
Bill (proposed law)
A bill is a proposed law under consideration by a legislature. A bill does not become law until it is passed by the legislature and, in most cases, approved by the executive. Once a bill has been enacted into law, it is called an act or a statute....
to make C. geaster the official state fungus of Texas. The bill passed the Senate
Texas Senate
The Texas Senate is the upper house of the Texas Legislature. There are 31 members of the Senate, representing 31 single-member districts across the state with populations of approximately 672,000 per constituency. There are no term limits, and each term is four years long. The Senate meets at the...
but did not succeed in the House
Texas House of Representatives
The Texas House of Representatives is the lower house of the Texas Legislature. The House is composed of 150 members elected from single-member districts across the state. The average district has about 150,000 people. Representatives are elected to two-year terms with no term limits...
. In Japan the mushroom is called kirinomitake (キリノミタケ), because the immature, unopened fruit body bears some resemblance to the seed pods of kiri, the Empress tree (Paulownia tomentosa
Paulownia tomentosa
Paulownia tomentosa is a deciduous tree in the genus Paulownia, native to central and western China, but invasive in the US...
).
Description
Young specimens of C. geaster have a hollow, club-shaped dark-brown fruit body, connected to a stemStipe (mycology)
thumb|150px|right|Diagram of a [[basidiomycete]] stipe with an [[annulus |annulus]] and [[volva |volva]]In mycology a stipe refers to the stem or stalk-like feature supporting the cap of a mushroom. Like all tissues of the mushroom other than the hymenium, the stipe is composed of sterile hyphal...
. The stem, which is usually buried in the ground, is shorter than the hollow fruit body or equals it in length, although the stem length is somewhat variable depending on the depth of the underground root to which it is attached. The flesh
Trama (mycology)
In mycology trama is a term for the inner, fleshy portion of a mushroom's basidiocarp, or fruit body. It is distinct from the outer layer of tissue, known as the pileipellis or cuticle, and from the spore-bearing tissue layer known as the hymenium....
of the stem and the wall of the fruit body is white, while the inner surface is yellowish-white, turning light brown with age. The fruit body varies in width from 1.2 to 3.5 cm (0.47244094488189 to 1.4 in) in the thickest portion, and has a length of 4 to 12 cm (1.6 to 4.7 ); the stem is 0.75 to 1.5 cm (0.295275590551181 to 0.590551181102362 in) wide by 1 to 5 cm (0.393700787401575 to 2 in) long. Both stem and fruit body are covered by a dense layer of soft brown velvety "hairs", or tomentum. In maturity, the fruit body splits open into 4–7 rays that curve downward, similar to mushrooms of the genus 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....
. The spores are borne on the inner surface of the rays, which, depending on the maturity of the specimen, may range in color from whitish to saffron
Saffron (color)
Saffron is a color that is a tone of golden yellow resembling the color of the tip of the saffron crocus thread, from which the spice saffron is derived.The first recorded use of saffron as a color name in English was in 1200...
to salmon
Salmon (color)
Salmon a range of pale pinkish-orange to light pink colors, named after the color of salmon flesh.The web color salmon is displayed at right.The first recorded use of salmon as a color name in English was in 1776...
to butterscotch to chestnut
Chestnut (color)
Chestnut, also known as Indian red, is a color, a medium brownish shade of red, and is named after the nut of the chestnut tree.As Indian red, it is named after the red laterite soil found in India. It is thus an earth tone as well as a red. It is composed of naturally occurring iron oxides. Other...
. The leathery rays are up to 0.35 cm (0.137795275590551 in) thick.
The fruit body remains closed until shortly before spore discharge; 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...
(fruit body opening) is caused by the pressure exerted by swollen paraphyses
Paraphyses
Paraphyses are part of the fertile spore-bearing layer in certain fungi. More specifically, paraphyses are sterile filamentous hyphal end cells composing part of the hymenium of Ascomycota and Basidiomycota interspersed among either the asci or basidia respectively, and not sufficiently...
—sterile (i.e., non-reproductive) cells that are interspersed between the ascospore
Ascospore
An ascospore is a spore contained in an ascus or that was produced inside an ascus. This kind of spore is specific to fungi classified as ascomycetes ....
s. Dehiscence is accompanied by the release of clouds of spores resembling dust; the characteristic shape of the unopened fruit body, as well as the smoky spore release give the fungus its common name "Devil's cigar". The spore puffing upon rupture is thought to be caused by the sudden change in relative humidity between the interior chamber of the fruit body and the outside environment. Dehiscence is accompanied by a hissing sound, an auditory phenomenon known to occur in about fifteen other fungal species.
Microscopic characteristics
SporesAscospore
An ascospore is a spore contained in an ascus or that was produced inside an ascus. This kind of spore is specific to fungi classified as ascomycetes ....
are oblong to spindle-shaped, and are flattened on one side; they have dimensions of 54–68 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...
by 10–13 µm. The spores each contain 3–5 oil drops. Although the spores have been described as smooth in older literature, when viewed with transmission electron microscopy
Transmission electron microscopy
Transmission electron microscopy is a microscopy technique whereby a beam of electrons is transmitted through an ultra thin specimen, interacting with the specimen as it passes through...
, they are seen to have minute spots or punctures. The spores develop simultaneously (synchronously) within the ascus
Ascus
An ascus is the sexual spore-bearing cell produced in ascomycete fungi. On average, asci normally contain eight ascospores, produced by a meiotic cell division followed, in most species, by a mitotic cell division. However, asci in some genera or species can number one , two, four, or multiples...
, a developmental feature shared with the Sarcoscyphaceae
Sarcoscyphaceae
The Sarcoscyphaceae are a family of cup fungi in the Pezizales order. There are 13 genera and 102 species in the family. Members of this family are cosmopolitan in distribution, being found in both tropical and temperate regions.-External links:...
genera Cookeina
Cookeina
Cookeina is a genus of cup fungi in the family Sarcoscyphaceae, members of which may be found in tropical and subtropical regions of the world. Species may be found on fallen branches of angiosperms, trunks, and sometimes on fruits...
and Microstoma. Like other members of the Pezizales
Pezizales
The Pezizales are an order of the subphylum Pezizomycotina within the phylum Ascomycota. The order contains 16 families, 199 genera, and 1683 species. It contains a number of species of economic importance, such as morels, the black and white truffles, and the desert truffles. The Pezizales are...
order, the asci
Ascus
An ascus is the sexual spore-bearing cell produced in ascomycete fungi. On average, asci normally contain eight ascospores, produced by a meiotic cell division followed, in most species, by a mitotic cell division. However, asci in some genera or species can number one , two, four, or multiples...
of C. geaster have an operculum
Operculum (botany)
An operculum, in botany, is a term generally used to describe a structure within a plant, moss, or fungus acting as a cap, flap, or lid. In plants, it may also be called a bud cap.Examples of structures identified as opercula include:...
—a "lid"—that opens when the spores are discharged. However, the operculum of C. geaster develops a two-layered ring zone upon dehiscence, making it structurally distinct from members of both the Sarcosomataceae
Sarcosomataceae
The Sarcosomataceae are a family of fungi in the order Pezizales. According to a 2008 estimate, the family contains 10 genera and 57 species. Most species are found in temperate areas, and are typically saprobic on rotten or buried wood....
and the Sarcoscyphaceae
Sarcoscyphaceae
The Sarcoscyphaceae are a family of cup fungi in the Pezizales order. There are 13 genera and 102 species in the family. Members of this family are cosmopolitan in distribution, being found in both tropical and temperate regions.-External links:...
families.
Similar to other Discomycetes, the fruit body consists of three distinct layers of tissue: the hymenium
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...
, the hypothecium, and the excipulum. The spore-bearing hymenium, the outermost layer of cells, contains asci interspersed with sterile cells called paraphyses
Paraphyses
Paraphyses are part of the fertile spore-bearing layer in certain fungi. More specifically, paraphyses are sterile filamentous hyphal end cells composing part of the hymenium of Ascomycota and Basidiomycota interspersed among either the asci or basidia respectively, and not sufficiently...
. In C. geaster, the club-shaped asci are 700–800 µm long and 14–17.25 µm thick; they are abruptly constricted at the base to a narrow pedicel. The paraphyses are initially filamentous or thread-like (filiform) but swell with age to resemble a string of beads (monoliform). The swelling of the paraphyses is believed to cause the expansion of the hymenium and subsequent splitting of the fruit body into rays; this development places the asci into an optimal position for spore release and dispersal. Supporting the cells of the hymenium is a thin layer of tightly interwoven hypha
Hypha
A hypha is a long, branching filamentous structure of a fungus, and also of unrelated Actinobacteria. In most fungi, hyphae are the main mode of vegetative growth, and are collectively called a mycelium; yeasts are unicellular fungi that do not grow as hyphae.-Structure:A hypha consists of one or...
e called the hypothecium, and underneath this is a thick layer of loosely-interwoven hyphae known as the exipulum. This tissue layer, analogous to parenchyma found in plants, gives the tissue a fibrous texture. The exipulum layer averages 34 µm in diameter, while the hypothecium is 10–14 µm. When viewed with electron microscopy
Electron microscope
An electron microscope is a type of microscope that uses a beam of electrons to illuminate the specimen and produce a magnified image. Electron microscopes have a greater resolving power than a light-powered optical microscope, because electrons have wavelengths about 100,000 times shorter than...
, the dark brown "hairs" on the surface of the fruit body can be seen to be adorned with conical warts or spines.
Anamorph form
The so-called anamorphic or imperfect fungiFungi imperfecti
The Fungi imperfecti or imperfect fungi, also known as Deuteromycota, are fungi which do not fit into the commonly established taxonomic classifications of fungi that are based on biological species concepts or morphological characteristics of sexual structures because their sexual form of...
are those that seem to lack a sexual stage in their life cycle
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...
, and typically reproduce by the process of mitosis
Mitosis
Mitosis is the process by which a eukaryotic cell separates the chromosomes in its cell nucleus into two identical sets, in two separate nuclei. It is generally followed immediately by cytokinesis, which divides the nuclei, cytoplasm, organelles and cell membrane into two cells containing roughly...
in structures called conidia
Conidium
Conidia, sometimes termed conidiospores, are asexual, non-motile spores of a fungus and are named after the greek word for dust, konia. They are also called mitospores due to the way they are generated through the cellular process of mitosis...
. In some cases, the sexual stage—or teleomorph
Teleomorph, anamorph and holomorph
The terms teleomorph, anamorph, and holomorph apply to portions of the life cycles of fungi in the phyla Ascomycota and Basidiomycota.*Teleomorph: the sexual reproductive stage , typically a fruiting body....
stage—is later identified, and a teleomorph-anamorph relationship is established between the species. The International Code of Botanical Nomenclature permits the recognition of two (or more) names for one and the same organisms, one based on the teleomorph, the other(s) restricted to the anamorph. In 2004, researchers reported a connection between C. geaster and the appearance of blackish-brown tufted structures on rotting wood. By comparing the internal transcribed spacer
Internal transcribed spacer
ITS refers to a piece of non-functional RNA situated between structural ribosomal RNAs on a common precursor transcript. Read from 5' to 3', this polycistronic rRNA precursor transcript contains the 5' external transcribed sequence , 18S rRNA, ITS1, 5.8S rRNA, ITS2, 28S rRNA and finally the 3'ETS...
region of the nuclear ribosomal DNA
Ribosomal DNA
Ribosomal DNA codes for ribosomal RNA. The ribosome is an intracellular macromolecule that produces proteins or polypeptide chains. The ribosome itself consists of a composite of proteins and RNA. As shown in the figure, rDNA consists of a tandem repeat of a unit segment, an operon, composed of...
from the two organisms, they established a phylogenetic
Phylogenetics
In biology, phylogenetics is the study of evolutionary relatedness among groups of organisms , which is discovered through molecular sequencing data and morphological data matrices...
connection between Chorioactis and the fungus they called Conoplea
Conoplea
Conoplea is a genus of fungi first described by Christian Hendrik Persoon in 1801. The eight members of the genus are anamorphic versions of Sarcosomataceae species.-External links:* at Index Fungorum...
aff. elegantula. However, they were unable to induce the new organism to grow on artificial media, and did not definitively establish a teleomorph-anamorph connection between the fungi. In 2009, Japanese researchers found a similar fungus growing on rotting logs that were normally associated with the growth of C. geaster; they were able to grow the organism in axenic cultures
Axenic
In biology, axenic describes a culture of an organism that is entirely free of all other "contaminating" organisms. The earliest axenic cultures were of bacteria or unicellular eukaryotes, but axenic cultures of many multicellular organisms are also possible...
from single-spore isolates of C. geaster. They named the anamorph Kumanasamuha geaster due to its 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....
similarity with species in the genus Kumanasamuha.
Distribution, ecology, and habitat
Chorioactis geaster has a disjunct distributionDisjunct distribution
In biology, a taxon with a disjunct distribution is one that has two or more groups that are related but widely separated from each other geographically...
, and has only been collected from Texas
Texas
Texas is the second largest U.S. state by both area and population, and the largest state by area in the contiguous United States.The name, based on the Caddo word "Tejas" meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in...
and Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
. The first reported collection in Japan was in Kyushu
Kyushu
is the third largest island of Japan and most southwesterly of its four main islands. Its alternate ancient names include , , and . The historical regional name is referred to Kyushu and its surrounding islands....
in 1937, and then it was not collected again in that location until thirty-six years later. In 2006, it was observed in a humid forest near Kawakami
Kawakami, Nara
is a village located in Yoshino District, Nara, Japan.As of 2003, the village has an estimated population of 2,286 and a density of 8.49 persons per km². The total area is 269.16 km².-External links:*...
, Nara Prefecture
Nara Prefecture
is a prefecture in the Kansai region on Honshū Island, Japan. The capital is the city of Nara.-History:The present-day Nara Prefecture was created in 1887, making it independent of Osaka Prefecture....
. The fungus's natural habitat in Japan is disappearing because of the practice of deforestation
Deforestation
Deforestation is the removal of a forest or stand of trees where the land is thereafter converted to a nonforest use. Examples of deforestation include conversion of forestland to farms, ranches, or urban use....
and replanting with Japanese cedar (Cryptomeria japonica
Cryptomeria
Cryptomeria is a monotypic genus of conifer in the cypress family Cupressaceae formerly belonging to the family Taxodiaceae; it includes only one species, Cryptomeria japonica . It is endemic to Japan, where it is known as Sugi...
). This rare mushroom has been put on the list of 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 Japan. In Texas, the fungus has been reported in Collin County
Collin County, Texas
As of the census of 2000, there were 491,675 people, 181,970 households, and 132,292 families residing in the county. The population density was 580 people per square mile . There were 194,892 housing units at an average density of 230 per square mile...
, Hays
Hays County, Texas
Hays County is a county located on the Edwards Plateau in the U.S. state of Texas. In 2010, its official population had reached 157,107. It is named for John Coffee Hays, a Texas Ranger and Mexican-American War officer. The seat of the county is San Marcos....
, Travis
Travis County, Texas
As of 2009, the U.S. census estimates there were 1,026,158 people, 320,766 households, and 183,798 families residing in the county. The population density was 821 people per square mile . There were 335,881 housing units at an average density of 340 per square mile...
, Dallas, Denton
Denton County, Texas
Denton County is a county located in the U.S. state of Texas. In 2000, its population was 432,976; in 2009 the estimated population had reached 628,300. Part of the Dallas – Fort Worth Metroplex, it is one of the fastest-growing counties in the United States. The county seat is Denton. The county...
, Guadalupe
Guadalupe County, Texas
Guadalupe County is a county located in the U.S. state of Texas. In 2000, its population was 89,023. It is named for the Guadalupe River. The seat of the county is Seguin. It was founded in 1846....
, Tarrant
Tarrant County, Texas
Tarrant County is a county located in the U.S. state of Texas. As of the 2010 U.S. Census, it had a population of 1,809,034. Its county seat is Fort Worth. Tarrant County is the sixteenth most populous county in the United States and the third most populous in Texas. The county is named in honor...
and Hunt
Hunt County, Texas
As of the census of 2000, there were 76,596 people, 28,742 households, and 20,521 families residing in the county. The population density was 91 people per square mile . There were 32,490 housing units at an average density of 39 per square mile...
Counties. Travis, Hays, and Guadalupe counties are in central Texas, while the remainder are clustered together in the northeastern part of the state. Although the species is considered rare due to its globally restricted distribution, it may be locally abundant.
Detritivore
Detritivores, also known as detritophages or detritus feeders or detritus eaters or saprophages, are heterotrophs that obtain nutrients by consuming detritus . By doing so, they contribute to decomposition and the nutrient cycles...
, deriving nutrients from decomposing organic matter. In Texas, fruit bodies are found growing singly or in groups from roots, stumps, and dead roots of cedar elm trees (Ulmus crassifolia) or Symplocos myrtacea
Symplocos myrtacea
Symplocos myrtacea, commonly known as Japanese sapphireberry or in Japanese Hai-no-ki ハイノキ, is a tree native to Japan.It has been recorded as a host for the rare fungus Chorioactis geaster....
; in Japan, the usual host is dead oak trees
Oak
An oak is a tree or shrub in the genus Quercus , of which about 600 species exist. "Oak" may also appear in the names of species in related genera, notably Lithocarpus...
. Fruit bodies can be clustered together close to the base of the stump, or from the roots away from the stump; the stem
Stipe (mycology)
thumb|150px|right|Diagram of a [[basidiomycete]] stipe with an [[annulus |annulus]] and [[volva |volva]]In mycology a stipe refers to the stem or stalk-like feature supporting the cap of a mushroom. Like all tissues of the mushroom other than the hymenium, the stipe is composed of sterile hyphal...
of the fruit body tends to originate from a point 5 to 10 cm (2 to 3.9 in) below the ground. In Texas, fruit bodies usually appear between October and April, as this period is associated with somewhat cooler weather, and the temperature and moisture conditions during this time seem to be more favorable for growth.
Scientists do not know why the fungus mysteriously lives only in Texas and Japan, locations of approximately the same latitude
Latitude
In geography, the latitude of a location on the Earth is the angular distance of that location south or north of the Equator. The latitude is an angle, and is usually measured in degrees . The equator has a latitude of 0°, the North pole has a latitude of 90° north , and the South pole has a...
, but separated by 11000 km (6,835.1 mi). Fred Jay Seaver commented "this is only another illustration of the unusual and unpredictable distribution of many species of the fungi. It would be difficult indeed to account for it, and we merely accept the facts as they are." In 2004, a research study compared the DNA sequences of both populations and used a combination of molecular phylogenetics and molecular clock
Molecular clock
The molecular clock is a technique in molecular evolution that uses fossil constraints and rates of molecular change to deduce the time in geologic history when two species or other taxa diverged. It is used to estimate the time of occurrence of events called speciation or radiation...
calculations to estimate the extent of genetic divergence. It concluded that the two populations have been separated for at least nineteen million years, ruling out the possibility of human introduction of the species from one location to the other. Although there are no consistent differences in 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....
between the two populations, there are several differences in their life histories
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...
. The preferred host of Texan populations is typically roots and stumps of Ulmus crassifola, while the Japanese populations tend to grow on the fallen trunks of Symplocos myrtaceae and Quercus gilva. Texan species grow in areas subjected to periodic flooding, unlike their Japanese counterparts. Finally, only Japanese specimens can be grown in culture—the spores of Texan material have not been successfully germinated on artificial media
Growth medium
A growth medium or culture medium is a liquid or gel designed to support the growth of microorganisms or cells, or small plants like the moss Physcomitrella patens.There are different types of media for growing different types of cells....
.
External links
- River Legacy Parks, Arlington, Texas
- YouTube video
- キリノミタケ Chorioactis geaster by I. Asai - several photos