Astraeus | |
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Astraeus hygrometricus | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Fungi |
Division: | Basidiomycota |
Class: | Agaricomycetes |
Order: | Boletales |
Family: | Diplocystaceae |
Genus: | Astraeus Morgan (1885) |
Type species | |
Astraeus hygrometricus (Pers.) Morgan (1889) | |
Species | |
A. asiaticus Contents |
Astraeus is a genus of fungi in the family Diplocystaceae. [1] The genus, which has a cosmopolitan distribution, contains nine species of earthstar mushroom. [2] They are distinguished by the outer layer of flesh (exoperidium) that at maturity splits open in a star-shape manner to reveal a round spore sac. [3] Additionally, they have a strongly hygroscopic character—the rays will open when moist, but when hot and dry will close to protect the spore sac. Species of Astraeus grow on the ground in ectomycorrhizal associations with trees and shrubs. [4] Despite their similar appearance to the Geastrum earthstars, the species of Astraeus are not closely related.
The mycelium of immature specimens is fibrous, and originates from all parts of the surface. The peridium is roughly spherical, and made of two distinct tissue layers. The outer layer, the exoperidium, is thick, leathery, and initially inseparable from the inner layer (endoperidium). At maturity, the exoperidium bursts open into several pointed "rays". The inner layer of tissue, the endoperidium, is thin, like a membrane. The spore case enclosed by the endoperidium has no stalk (sessile), and is opened at the top by a tear or pore. Microscopically, sterile cells, long-threaded cells called capillitium originate from the inner surface of the peridium; they are highly branched and interwoven. The spores are large, spherical, minutely warted, and brown. [5] Astraeus species are strongly hygroscopic, and absorb moisture from the environment, so that the rays are closed over the spore case when dry, but open up flat when moistened.
The genus Astraeus was first described by the American mycologist and botanist Andrew Price Morgan in 1885. [6] The outward resemblance of Astraeus species with those from genus Geaster (family Geastraceae) has led several authors to place them in that genus. [7]
Phylogenetic analyses proved that the genus Astraeus together with the genera Boletinellus , Phlebopus , Pisolithus , Calostoma , Gyroporus , Scleroderma , and Veligaster , form a distinct phylogenetic lineage in the Boletales; these genera collectively form the suborder Sclerodermatineae. [8] The similarity between Geastrum and Astraeus species is an example of convergent evolution. [4] Astraeus is currently classified in the family Diplocystaceae. [9]
For a long time, the genus Astraeus was thought to contain at most two species. [10] However, studies in the 2000s showed that species collected from around the world and labelled under the specific epithet hygrometricus were actually considerably variable in a number of macroscopic and microscopic characteristics. [11] A molecular study of the DNA sequences of the ITS region of the ribosomal DNA from a number of Astraeus specimens from around the world has helped to establish the phylogenetic relationships within the genus. Currently, eight species are recognized: [12] [13]
In 2008, five lanostane-type triterpenes were isolated and identified from the fruit bodies of A. pteridis; two of these compounds had an inhibitory effect on the growth of the pathogen Mycobacterium tuberculosis . [15]
The Sclerodermataceae are a family of fungi in the order Boletales, containing several genera of unusual fungi that little resemble boletes. Taxa, which include species commonly known as the ‘hard-skinned puffballs’, ‘earthballs’, or 'earthstars', are widespread in both temperate and tropical regions. The best known members include the earthball Scleroderma citrinum, the dye fungus Pisolithus tinctorius and the 'prettymouths' of the genus Calostoma.
Calostoma is a genus of 29 species of gasteroid fungi in the suborder Sclerodermatineae. Like other gasteroid fungi, Calostoma do not have the spore discharge mechanism associated with typical gilled fungi (ballistospory), and instead have enclosed spore-bearing structures. Resembling round puffballs with raised, brightly colored spore openings (ostioles), elevated on a thick, gelatinous stalks, species have been collected in regions of deciduous, temperate, tropical or subtropical forests. Their distribution includes eastern North America, Central America, Asia, and Australasia. The common name given to some species, "prettymouth", alludes to the brightly colored raised openings (ostioles) that may somewhat resemble lips. Other common names include "hotlips" and "puffball in aspic".
Bovista is a genus of fungi commonly known as the true puffballs. It was formerly classified within the now-obsolete order Lycoperdales, which, following a restructuring of fungal taxonomy brought about by molecular phylogeny, has been split; the species of Bovista are now placed in the family Agaricaceae of the order Agaricales. Bovista species have a collectively widespread distribution, and are found largely in temperate regions of the world. Various species have historically been used in homeopathic preparations.
Sphaerobolus is a genus of fungi in the family Geastraceae. Commonly known as the "shotgun fungus", "artillery fungus" or "cannonball fungus", species discharge their spores with explosive force. Discharged spore sacs are sticky and have a tendency to strongly adhere to whatever surface they encounter, making them a nuisance to homeowners, pressure washing contractors, landscape mulch producers and insurance companies.
The peridium is the protective layer that encloses a mass of spores in fungi. This outer covering is a distinctive feature of gasteroid fungi.
Myriostoma is a fungal genus in the family Geastraceae. Basidiocarps resemble earthstars, but the spore sac is supported by multiple columns and has multiple ostioles instead of a single, apical ostiole. Until 2017, the genus was thought to be monotypic with a single, widespread species, Myriostoma coliforme. Recent research has, however, shown that at least six species occur worldwide.
Geastrum saccatum, commonly known as the sessile earthstar or rounded earthstar, or star of the land, is a species of mushroom belonging to the genus Geastrum. The opening of the outer layer of the fruiting body in the characteristic star shape is thought to be due to a buildup of calcium oxalate crystals immediately prior to dehiscence. G. saccatum is distinguished from other earthstars by the distinct circular ridge or depression surrounding the central pore.
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 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 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. Spores are spherical, measuring 4 to 6 micrometers in diameter, with warts on their surfaces.
Astraeus hygrometricus, commonly known as the hygroscopic earthstar, the barometer earthstar, or the false earthstar, is a species of fungus in the family Diplocystaceae. Young specimens resemble a puffball when unopened. In maturity, the mushroom displays the characteristic earthstar shape that is a result of the outer layer of fruit body tissue splitting open in a star-like manner. The false earthstar is an ectomycorrhizal species that grows in association with various trees, especially in sandy soils. A. hygrometricus was previously thought to have a cosmopolitan distribution, though it is now thought to be restricted to Southern Europe, and Astraeus are common in temperate and tropical regions. Its common names refer to the fact that it is hygroscopic (water-absorbing) and can open up its rays to expose the spore sac in response to increased humidity, then close them up again in drier conditions. The rays have an irregularly cracked surface, while the spore case is pale brown and smooth with an irregular slit or tear at the top. The gleba is white initially, but turns brown and powdery when the spores mature. The spores are reddish-brown and roughly spherical with minute warts, measuring 7.5–11 micrometers in diameter.
Geasteroides is a fungal genus in the family Geastraceae. A monotypic genus, it contains the single species Geasteroides texensis, described by American mycologist William Henry Long in 1917.
Geastrum triplex is a fungus found in the detritus and leaf litter of hardwood forests around 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 and expanded mature specimens can reach a tip-to-tip length of up to 12 centimeters.
The gasteroid fungi are a group of fungi in the Basidiomycota. Species were formerly placed in the obsolete class Gasteromycetes Fr., or the equally obsolete order Gasteromycetales Rea, because they produce spores inside their basidiocarps rather than on an outer surface. However, the class is polyphyletic, as such species—which include puffballs, earthstars, stinkhorns, and false truffles—are not closely related to each other. Because they are often studied as a group, it has been convenient to retain the informal (non-taxonomic) name of "gasteroid fungi".
Geastrum jurei is a species of fungus in the Geastrales, or earthstar fungi. It is known only from Algarrobo, in the Valparaíso province of Chile. It is a fornicate species of earthstar, meaning that the tips of the rays press down so as to raise the spherical spore sac into the air.
Geastrum quadrifidum, commonly known as the rayed earthstar or four-footed earthstar, is an inedible species of mushroom belonging to the genus Geastrum, or earthstar fungi. First described scientifically by Christian Hendrik Persoon in 1794, G. quadrifidum is a cosmopolitan—but not common—species of Europe, the Americas, Africa, Asia, and Australasia. The fungus is a saprobe, feeding off decomposing organic matter present in the soil and litter of coniferous forests.
Geastrum welwitschii is a species of fungus in the earthstar family. First collected from Spain in the mid-19th century, the fungus is distributed in Europe, North America, and Bermuda.
Astraeus asiaticus is a species of false earthstar in the family Diplocystaceae. Described as a new species in 2007, it was originally found in north and northeastern areas of Thailand, where it grows in sandy or laterite-rich soil in dry lowland dipterocarp forests. The species has a wide distribution in Asia.
Astraeus odoratus is a species of false earthstar in the family Diplocystaceae. Described as a new species in 2004, it was originally found in the Thai highlands growing in sandy or laterite-rich soil in dry lowland dipterocarp forests. The species is found in Southeast Asia.
Astraeus pteridis, commonly known as the giant hygroscopic earthstar, is a species of false earthstar in the family Diplocystaceae. It was described by American mycologist Cornelius Lott Shear in 1902 under the name Scleroderma pteridis. Sanford Myron Zeller transferred it to Astraeus in a 1948 publication. It is found in North America. A. pteridis was previously frequently confused with the supposedly cosmopolitan A. hygrometricus, now shown to be found only in Europe.
Sclerodermatineae is a suborder of the fungal order Boletales. Circumscribed in 2002 by mycologists Manfred Binder and Andreas Bresinsky, it contains nine genera and about 80 species. The suborder contains a diverse assemblage fruit body morphologies, including boletes, gasteroid forms, earthstars, and puffballs. Most species are ectomycorrhizal, although the ecological role of some species is not known with certainty. The suborder is thought to have originated in the late Cretaceous (145–66 Ma) in Asia and North America, and the major genera diversified around the mid Cenozoic (66–0 Ma).
Astraeus sirindhorniae is a species of false earthstar in the family Diplocystaceae. A. sirindhorniae can be distinguished from close relatives A. odoratus, A. asiaticus and A. hygrometricus by differences in fruit body size, spore size, spore ornamentation, and peridium structure. The fungus was discovered in Phu Khieo Wildlife Sanctuary in northeastern Thailand, as part of a project to document the biodiversity of mycorrhizal fungi. The specific epithet sirindhorniae honors Princess Maha Chakri Sirindhorn on the occasion the 84th birthday of her father, King Bhumibol Adulyadej. Known only from north and northeastern Thailand, A. sirindhorniae is suspected to be ectomycorrhizal with members of the Dipterocarpaceae, although this has not yet been proven.