Geastrum saccatum

Last updated

Geastrum saccatum
Geastrum 20070721.jpg
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Fungi
Division: Basidiomycota
Class: Agaricomycetes
Order: Geastrales
Family: Geastraceae
Genus: Geastrum
Species:
G. saccatum
Binomial name
Geastrum saccatum
Fr. (1829)
Geastrum Saccatum
Information icon.svg
Gleba icon.png Glebal hymenium
No cap icon.svgNo distinct cap
Transparent spore print icon.svg
Spore print is brown
Saprotrophic fungus.svgEcology is saprotrophic
Mycomorphbox Inedible.pngEdibility is inedible

Geastrum saccatum, commonly known as the rounded earthstar, [1] is a species of mushroom belonging to the genus Geastrum . It has a worldwide distribution and is found growing on rotting wood. It is considered inedible by mushroomers because of its bitter taste. It is a common mushroom, but collections are at their peak during late summer. 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. In Brazil, its common name translates to "star of the land". [2]

Contents

Description

Specimen from Tasmania, Australia Geastrum saccatum.jpg
Specimen from Tasmania, Australia

The immature fruiting body is 0.6 to 2.5 centimetres (14 to 1 in) in diameter and 0.8 to 1.5 cm (38 to 58 in) tall. Initially, the fruiting body is egg-shaped—similar in appearance to puffballs—and has strands of mycelia (rhizomorphs) at the base that attach it to the growing surface. The 'skin,' or peridium, is composed of two separate layers: the outer layer (exoperidium), which is a golden tan to yellowish-brown color, separates away from the inner basidiocarp and splits into five to eight rays [3] that curve backward (recurve) to the base. The mushroom is 2 to 5 cm (34 to 2 in) in diameter after the rays have expanded. Unlike some other members of the genus Geastrum (such as G. fornicatum ) the arms do not push the basidiocarp off the ground; rather, it lies flat. The inner spore-bearing basidiocarp is 0.5 to 2 cm (14 to 34 in) broad, and has a central pore surrounded by a circular dull-brown apical disc; the disc is distinctly ridged or depressed. [1] The inside of the interior sphere is white when young, but matures into a mass of brown, powdery spores mixed with thick-walled fibres known as capillitium. [4] The species is inedible. [5]

A fresh specimen of Geastrum saccatum Geastrum.Saccatum.002.jpg
A fresh specimen of Geastrum saccatum

Spores

The spores are rounded, with warts, and have dimensions of 3.54.5  µm. [4]

Habitat and distribution

Geastrum saccatum is saprobic, and grows scattered or clustered together in leaf litter of humus, usually in late summer and fall. It has a cosmopolitan distribution, and is well adapted to tropical regions. [2] It is common in Hawaiian dry forests. [6] The species has been collected in the United States, Argentina, Uruguay, Brazil, Canada, China, Congo, Cuba, Mexico, Panama, South Africa, West Africa, Tanzania, India, and Tobago. [7]

Mechanism of dehiscence

A study has shown that the formation of calcium oxalate crystals on the hyphae that form the endoperidial layer of the basidiocarp is responsible for the characteristic opening (dehiscence) of the outer peridial layers. [8] Calcium oxalate is a common compound found in many fungi, [9] including the earthstars. [10] Curtis Gates Lloyd was the first to note the presence of these crystals on the endoperidium of Geaster calceus (now known as Geastrum minimum). [11] The formation of calcium oxalate crystals stretches the layers of the outer walls, pushing the inner and outer layers of the peridium apart. [8]

Bioactive compounds

A β-glucan–protein complex extracted from Geastrum saccatum was isolated and analysed and shown to have antiinflammatory, antioxidant, and cytotoxic activities. It is suggested that the mechanism for the antiinflammatory activity is due to inhibition of the enzymes nitric oxide synthase and cyclooxygenase. [2]

Similar species

The related species Geastrum fimbriatum does not have an apical disc, [12] and its pores are slightly smaller. G. saccatum may be distinguished from G. indicum by the absence of loose tissue forming a collar around the base of the endoperidium. Other similar species include G. fornicatum and G. triplex . [12]

See also

Related Research Articles

<span class="mw-page-title-main">Puffball</span> Fungus

Puffballs are a type of fungus featuring a ball-shaped fruit body that bursts on contact or impact, releasing a cloud of dust-like spores into the surrounding area. Puffballs belong to the division Basidiomycota and encompass several genera, including Calvatia, Calbovista and Lycoperdon. The puffballs were previously treated as a taxonomic group called the Gasteromycetes or Gasteromycetidae, but they are now known to be a polyphyletic assemblage.

<i>Geastrum</i> Genus of fungi

Geastrum is a genus of puffball-like mushrooms in the family Geastraceae. Many species are commonly known as earthstars.

<i>Sphaerobolus</i> Genus of fungi

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.

<i>Geastrum fornicatum</i> Species of fungus

Geastrum fornicatum, common name known as the acrobatic earthstar or the arched earthstar, is an inedible species of mushroom in the family Geastraceae. Like other earthstar mushrooms, the thick outer skin splits open at maturity to expose the spore sac to the elements; the specific epithet fornicatum refers to the arched shape of the rays which extend downwards to rest on the mycelial sac and elevate the spore sac.

<span class="mw-page-title-main">Peridium</span> Protective layer enclosing a mass of spores in fungi

The peridium is the protective layer that encloses a mass of spores in fungi. This outer covering is a distinctive feature of gasteroid fungi.

<i>Myriostoma</i> Genus of 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 berkeleyi, or Berkeley's earthstar, is an inedible species of mushroom belonging to the genus Geastrum, or earthstar fungi. Despite being a very uncommon mushroom, it has a wide geographical distribution, having been documented in Northern and Eastern Europe, such as Austria, the Czech Republic, Denmark, Estonia, Finland, Great Britain, Hungary, the Netherlands, Poland, Slovakia, Spain, Sweden and Turkey, and parts of Eastern Asia, such as China and Japan. The species was thought extinct in Poland until it was discovered growing in a reserve near Chęciny. G. berkeleyi can be distinguished from other species of Geastrum by the flat bipyramidal shape of the calcium oxalate crystals found on its endoperidium.

Geastrum entomophilum is an inedible species of mushroom belonging to the genus Geastrum, or earthstar fungi. Found in northeast Brazil in 2008, the species was found with beetles inhabiting the spore sac, likely contributing to spore dissemination.

<i>Geastrum fimbriatum</i> Species of fungus

Geastrum fimbriatum, commonly known as the fringed earthstar or the sessile earthstar, is an inedible species of mushroom belonging to the genus Geastrum, or earthstar fungi. First described in 1829, the species has a widespread distribution, and is found in Asia, Europe, and the Americas. It is distinguished from other earthstars by the delicate fibers that line the circular pore at the top of its spore sac.

<i>Geastrum pectinatum</i> Species of fungus

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 (0.3 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. Spores are spherical, measuring 4 to 6 micrometers 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, Australia 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.

<i>Astraeus hygrometricus</i> Cosmopolitan species of fungus in the family Diplocystaceae.

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.

<i>Astraeus</i> (fungus) Genus of fungi

Astraeus is a genus of fungi in the family Diplocystaceae. The genus, which has a cosmopolitan distribution, contains nine species of earthstar mushroom. 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. 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. Despite their similar appearance to the Geastrum earthstars Astraeus is not closely related.

<i>Geastrum triplex</i> Species of fungus in the family Geastraceae

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 (4.7 in).

<span class="mw-page-title-main">Gasteroid fungi</span> Group of fungi

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".

<i>Geastrum jurei</i> Species of fungus

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.

<i>Geastrum quadrifidum</i> Species of fungus in the family Geastraceaea

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.

<i>Geastrum welwitschii</i> Species of fungus

Geastrum welwitschii is a species of fungus in the earthstar family. When young and unopened, the fruit bodies resemble small spheres lying in the soil. As the mushroom matures, the thick leathery outer layer of tissue splits star-like to form a number of fleshy arms, which curve downward to reveal the inner spore sac that contains the fertile tissue known as the gleba. The spore sac has a narrow grooved opening at the top where the spores are released. Fully expanded, the fruit bodies are up to 35 mm (1.4 in) wide and 58 mm (2.3 in) tall. First collected from Spain in the mid-19th century, the fungus is distributed in Europe, North America, and Bermuda.

<i>Myriostoma coliforme</i> Genus of fungus

Myriostoma coliforme is a fungal species 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. In the UK, its recommended English name is pepper pot. It has also been called "salt-shaker earthstar". The fungus has a north temperate distribution, but was formerly thought to be more widespread due to confusion with related Myriostoma species. Myriostoma coliforme is an uncommon species and appears on the Red Lists of 12 European countries. In 2004 it was one of 33 species proposed for protection under the Bern Convention by the European Council for Conservation of Fungi.

<i>Geastrum minimum</i> Species of fungus

Geastrum minimum or tiny earthstar is an inedible species of mushroom belonging to the genus Geastrum. Although rare, it is widespread in Europe, where it occurs in a range of habitats. It is a priority species in the UK, where it has been found in the sand dunes at Holkham National Nature Reserve.

Geastrum britannicum is a fungal species in the family Geastraceae. Its recommended English name is vaulted earthstar. Like other earthstars, the basidiocarps are initially globose. Their thick outer skin splits open at maturity to expose the puffball-like spore sac surrounded by the split rays of the outer skin. In the vaulted earthstar, the rays split apart and form an arch, raising the spore sac upwards.

References

  1. 1 2 Sundberg W, Bessette A (1987). Mushrooms: A Quick Reference Guide to Mushrooms of North America (Macmillan Field Guides). New York: Collier Books. p. 20. ISBN   0-02-063690-3.
  2. 1 2 3 Guerra Dore CM, Azevedo TC, de Souza MC, Rego LA, de Dantas JC, Silva FR, Rocha HA, Baseia IG, Leite EL (2007). "Antiinflammatory, antioxidant and cytotoxic actions of β-glucan-rich extract from Geastrum saccatum mushroom". International Immunopharmacology. 7 (9): 1160–9. doi:10.1016/j.intimp.2007.04.010. PMID   17630194.
  3. Trudell, Steve; Ammirati, Joe (2009). Mushrooms of the Pacific Northwest. Timber Press Field Guides. Portland, OR: Timber Press. p. 271. ISBN   978-0-88192-935-5.
  4. 1 2 Healy RA, Huffman DR, Tiffany LH, Knaphaus G (2008). Mushrooms and Other Fungi of the Midcontinental United States (Bur Oak Guide). Iowa City: University of Iowa Press. p. 243. ISBN   978-1-58729-627-7.
  5. Phillips, Roger (2010). Mushrooms and Other Fungi of North America. Buffalo, NY: Firefly Books. p. 336. ISBN   978-1-55407-651-2.
  6. Smith, Clifford W; Leon, Patricio Ponce de (1982). "Hawaiian geastroid fungi". Mycologia . 74 (5): 712–17. doi:10.2307/3792856. JSTOR   3792856.
  7. Baseia IG, Cavalcanti MA, Milanez AI (2003). "Additions to our knowledge of the genus Geastrum (Phallales: Geastraceae) in Brazil". Mycotaxon. 85: 409–15.
  8. 1 2 Whitney, Kenneth D; Arnott, Howard J (1986). "Calcium oxalate crystals and basidiocarp dehiscence in Geastrum saccatum (Gasteromycetes)". Mycologia. 78 (4): 649–56. doi:10.2307/3807778. JSTOR   3807778.
  9. Whitney, Kenneth D; Arnott, Howard J (1986). "Morphology and development of calcium oxalate deposits in Gilbertella persicaria (Mucorales)". Mycologia. 78 (1): 42–51. doi:10.2307/3793375. JSTOR   3793375.
  10. Horner HT, Tiffany LH, Cody AM (1983). "Calcium oxalate bipyramidal crystals on the basidiocarps of Geastrum minus (Lycoperdales)". Proceedings of the Iowa Academy of Sciences. 92 (2): 70–77.
  11. Lloyd CG. (1907). "New notes on the Geasters". Mycological Notes. 25: 309–17.
  12. 1 2 Davis, R. Michael; Sommer, Robert; Menge, John A. (2012). Field Guide to Mushrooms of Western North America. Berkeley: University of California Press. p. 371. ISBN   978-0-520-95360-4. OCLC   797915861.

Further reading