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.
Calcium oxalate (in archaic terminology, oxalate of lime) is a calcium salt of oxalic acid with the chemical formula CaC2O4 or Ca(COO)2. It forms hydrates CaC2O4·nH2O, where n varies from 1 to 3. Anhydrous and all hydrated forms are colorless or white. The monohydrate CaC2O4·H2O occurs naturally as the mineral whewellite, forming envelope-shaped crystals, known in plants as raphides. The two rarer hydrates are dihydrate CaC2O4·2H2O, which occurs naturally as the mineral weddellite, and trihydrate CaC2O4·3H2O, which occurs naturally as the mineral caoxite, are also recognized. Some foods have high quantities of calcium oxalates and can produce sores and numbing on ingestion and may even be fatal. Cultural groups with diets that depend highly on fruits and vegetables high in calcium oxalate, such as those in Micronesia, reduce the level of it by boiling and cooking them. They are a constituent in 76% of human kidney stones. Calcium oxalate is also found in beerstone, a scale that forms on containers used in breweries.
Raphides are needle-shaped crystals of calcium oxalate monohydrate or calcium carbonate as aragonite, found in more than 200 families of plants. Both ends are needle-like, but raphides tend to be blunt at one end and sharp at the other.
Geastrum is a genus of puffball-like mushrooms in the family Geastraceae. Many species are commonly known as earthstars.
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.
Geastrum saccatum, commonly known as the rounded earthstar, 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".
Geastrum australe is an inedible species of mushroom belonging to the genus Geastrum, or earthstar fungi. It can be mistaken for Geastrum saccatum or Geastrum simulans, and is found in Melbourne.
Geastrum campestre is an inedible species of mushroom belonging to the genus Geastrum, or earthstar fungi.
Geastrum corollinum is an inedible species of mushroom belonging to the genus Geastrum, or earthstar fungi. First described scientifically by German naturalist August Johann Georg Karl Batsch in 1792 as Lycoperdon corollinum, it was transferred to the genus Geastrum by László Hollós in 1904.
Geastrum coronatum is an inedible species of mushroom belonging to the genus Geastrum, or earthstar fungi. Christian Hendrik Persoon published the first description of Geastrum coronatum in 1801.
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.
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.
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.
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.
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).
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. 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.
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.
Geastrum aculeatum is a species of mushroom belonging to the genus Geastrum, or earthstar fungi. It is found in eastern Brazil.
