Marasmius rotula | |
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Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Fungi |
Division: | Basidiomycota |
Class: | Agaricomycetes |
Order: | Agaricales |
Family: | Marasmiaceae |
Genus: | Marasmius |
Species: | M. rotula |
Binomial name | |
Marasmius rotula | |
Synonyms [1] | |
Marasmius rotula | |
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Gills on hymenium | |
Cap is convex | |
Hymenium is free | |
Stipe is bare | |
Spore print is white | |
Ecology is saprotrophic | |
Edibility is inedible |
Marasmius rotula is a common species of agaric fungus in the family Marasmiaceae. Widespread in the Northern Hemisphere, it is commonly known variously as the pinwheel mushroom, the pinwheel marasmius, the little wheel, the collared parachute, or the horse hair fungus. The type species of the genus Marasmius , M. rotula was first described scientifically in 1772 by mycologist Giovanni Antonio Scopoli and assigned its current name in 1838 by Elias Fries.
The fruit bodies, or mushrooms, of M. rotula are characterized by their whitish, thin, and membranous caps up to 2 cm (3⁄4 in) wide that are sunken in the center, and pleated with scalloped margins. The slender and wiry black hollow stems measure up to 8 cm (3 in) long by 1.5 mm (1⁄16 in) thick. On the underside of the caps are widely spaced white gills that are attached to a collar encircling the stem. The mushrooms grow in groups or clusters on decaying wood such as fallen twigs and sticks, moss-covered logs, and stumps.
Although many mushrooms release their spores in response to a circadian rhythm, spore release in M. rotula is dependent upon sufficient moisture. Dried mushrooms may revive after rehydrating and continue to release spores for up to three weeks—a sustained spore production of markedly longer duration than other typical agarics. There are several species of Marasmius with which M. rotula might be confused due to somewhat similar overall appearances, but differences in size, gill arrangement, and substrate are usually sufficient field characteristics to distinguish them. M. rotula mushrooms are not generally considered edible. They produce a unique peroxidase enzyme that is attracting research interest for possible use in bioengineering applications.
The species was first described by Italian mycologist Giovanni Antonio Scopoli as Agaricus rotula in 1772. [4] In 1821 Elias Magnus Fries redescribed the mushroom in Systema Mycologicum , [5] and later transferred it to Marasmius in his 1838 Epicrisis Systematis Mycologici. [6] Synonyms include names derived from generic transfers to Androsaceus by Narcisse Théophile Patouillard in 1887, [7] and to Chamaeceras by Otto Kuntze in 1898; [3] both of these genera are now obsolete and have since been sunk back into Marasmius. [8]
In his 1821 A Natural Arrangement of British Plants, Samuel Frederick Gray introduced the generic name Micromphale, including the species Micromphale collariatum, [2] which was based on William Withering's 1796 Merulius collariatus. [9] In 1946 Alexander H. Smith and Rolf Singer proposed to conserve the name Marasmius over Micromphale; the latter had nomenclatorial priority as it was published first. [10] The generic name Marasmius, with M. rotula as the lectotype species, was later conserved at the 1954 Paris Congress on Botanical Nomenclature. [11] [12] M. rotula is also the type species of section Marasmius within the genus. This grouping of species is characterized by inamyloid flesh, a cap cuticle with broom cells (finger-like projections common to Marasmius species) ornamented with numerous warts, gills usually attached to a collar surrounding the stem, and the presence of black rhizomorphs on the stem. [13]
Several varieties of M. rotula have been described. Miles Berkeley and Moses Ashley Curtis named var. fuscus in 1869 for its brown cap. [14] In 1887 Pier Andrea Saccardo described var. microcephalus from Italy, with caps half the normal size. [15] It is now understood that fruit body morphology is variable and dependent upon environmental conditions. Joseph Schröter described var. phyllophyla in 1889, [16] but that taxon is now treated as Marasmius bulliardii . [17]
Marasmius rotula is commonly known as the "pinwheel mushroom", the "pinwheel Marasmius", [18] the "collared parachute", [19] or the "horse hair fungus". [20] This latter name is shared with other Marasmius species, including M. androsaceus [21] and M. crinis-equi . [22] Gray called it the "collared dimple-stool". [2] The name "little wheel fungus" is suggestive of the collar to which the gills are attached like the spokes of a wheel, [23] like the specific epithet, which is a diminutive of rota, the Latin word for "wheel". [18]
The cap of the fruit body is thin and membranous, measuring 3 to 20 mm (1⁄8 to 3⁄4 in) in diameter. [24] It has a convex shape slightly depressed in the center, conspicuous furrows in an outline of the gills, and scalloped edges. Young, unexpanded caps are yellowish brown; as the cap expands, the color lightens to whitish or light pinkish-white, [25] often with a darker, sometimes brown center. [26] The variety fusca has brown caps. [14] The white or slightly yellowish flesh is very thin, reaching about 0.25–1.5 mm thick in the central part of the cap, and even thinner at the margin. [27]
Gills are attached to a collar, never to the stem, although some specimens have the collar pressed close enough to it that this characteristic may be less obvious. [18] Widely spaced, they have the same whitish to pale yellow color as the flesh, and typically number between 16 and 22. [26] They are initially narrow, but thicken downward to about 1–3 mm at the exposed edge. [27] The stem is 1.2 to 8 cm (1⁄2 to 3 in) long and up to 0.15 cm (0.06 in) thick, with a smooth, sometimes shiny surface. [20] It is tough, hollow, and either straight or with some curving. The color is blackish-brown up to a lighter, almost translucent apex. The base of the stem may be connected to dark brown or black root-like rhizomorphs 0.1–0.3 mm thick. [27] Mature specimens display no veil. [20]
Note particularly the manner in which the hair-like stem is set into the tiny socket, the sparsity of the gill development, and the fine furrows and scallopings of the margin of the cap. A Swiss watchmaker could not excel such workmanship.
Louis C.C. Krieger [28]
Details of the fruit bodies' appearance, color in particular, are somewhat variable and dependent on growing conditions. For example, specimens growing on logs in oak and hickory forests in the spring tend to have more yellowish-white, depressed caps than those found in the same location in autumn, which are light yellow brown and more convex in shape. [27] The fruit body development of M. rotula is hemiangiocarpous, with an hymenium that is only partially enclosed by basidiocarp tissues. Robert Kühner showed that a cortina-like tissue covers the young gills before the expanding cap breaks away from the stem. In unfavorable weather conditions, the mushrooms may fail to develop normally and instead produce semi-gasteroid basidiocarps. [29]
Viewed in deposit, such as with a spore print, the spores of Marasmius rotula appear white or pale yellow. [25] Under an optical microscope, they are hyaline (translucent), teardrop- or pip-shaped, and have dimensions of 7–10 by 3–5 μm. [20] The basidia (spore-producing cells) are four-spored, club-shaped or nearly so, and 21–21 by 4–17 μm. Along the edge of the gill, interspersed among the basidia, are non-reproductive cells, the cheilocystidia; these are club-shaped with rough wart-like protuberances on the surface. [26] The gill edges further feature broom cells, which are variably shaped, thin-walled, and measure 7–32 by 2.5–20 μm. Their apical surfaces are covered with yellowish, blunt, and conical warts or incrustations 0.2–1.5 by 0.1–1 μm. [27]
There are several less-common species of Marasmius with which M. rotula might be confused due to somewhat similar overall appearances, but differences in size, gill arrangement, and substrate are usually sufficient field characteristics to distinguish between them. For example, Marasmius capillaris has a pale tan cap with a white center, and grows on oak leaves without forming clusters. [24] Furthermore, its cap is evenly rounded, unlike the pleated and furrowed cap of M. rotula, [30] and its stem is somewhat thinner (usually less than 0.3 mm) and slightly darker in color. [31]
M. rotula is distinguished from M. bulliardii by its larger size, and greater number of gills. [26] M. limosus is found in marshes, where it fruits on the dead stems of reeds and rushes. [32] Tetrapyrgos nigripes (formerly treated in Marasmius) has white caps that are 5 to 10 mm (3⁄16 to 3⁄8 in) in diameter, attached gills that are sometimes slightly decurrent, a dark stem covered with tiny white hairs that give it a powdered appearance, and triangular to star-shaped spores. [33] M. neorotula , described from Brazil, was considered by its discoverer Rolf Singer to be closely related to M. rotula. In addition to its tropical distribution, it can be distinguished from M. rotula by its smaller size and more widely spaced gills. [34] M. rotuloides , known only from montane forests of Trinidad, can only be reliably distinguished from M. rotula by microscopic characteristics: it has smaller, ovoid spores measuring 5 by 2.5 μm. [35]
Other Marasmius species with a pinwheel arrangement of gills are readily distinguished from M. rotula by differences in color, including the orange M. siccus , the pink M. pulcherripes , and the rust M. fulvoferrugineus . [30] Mycena corticola is smaller than Marasmius rotula, has a pale pink-brown cap, and is usually found growing singly or in small groups on bark near the base of living trees. [18]
Marasmius rotula grows in deciduous forests and fruits in groups or clusters on dead wood (especially beech), woody debris such as twigs or sticks, and occasionally on rotting leaves. [23] The fruit bodies, which are easily overlooked because of their diminutive size, [23] are often present in abundance after rains. [36]
The fungus is widespread and common in its preferred habitats in North America, Europe, and northern Asia. [32] Although far less common in southerly locations, isolated collections have been reported from Africa (Congo, [37] Nigeria, [38] Sierra Leone, [39] and Tanzania) [40] and South Asia (India). [41] In North America M. rotula is most common in the eastern part of the continent. [20]
Marasmius rotula is a saprobic species [30] and as such obtains nutrients by decomposing dead organic matter. [23] The species is relatively intolerant of low water potentials, and will grow poorly or not at all under water stress conditions. [42] [43] It is unable to degrade leaf litter until it becomes more fragmented and more compacted so that the water-holding capacity increases in the deeper layers of the soil. [42] The magnolia warbler has been noted to line its nests with the fruit bodies' stems. [44]
In 1975 the American mycologist Martina S. Gilliam investigated the periodicity of spore release in M. rotula and concluded that spore discharge did not follow a regular circadian rhythm, as is typical of agaric and bolete mushrooms, [45] but rather was dependent on rain. A threshold of rainfall is required to elicit a spore discharge response and the duration of peak spore discharge correlates with the amount of rainfall, rather than its duration. Furthermore, Gilliam noted that spore prints were more readily obtained if the stem ends were placed in water, suggesting that water must enter through the fruit body for discharge to occur. [46]
Like those of many other species of Marasmius, the fruit bodies of M. rotula can desiccate and shrivel in dry periods, then revive when sufficient moisture is available again in the form of rain or high humidity. Gilliam's study demonstrated that revived fruit bodies were capable of discharging spores over a period of at least three weeks, whereas previous studies using similar methods with other Agaricomycetes showed spore discharge occurred over a shorter period of up to six days after revival. The potential for sustained spore production and discharge may be due to the growth of new basidioles (immature basidia) during periods of growth, which then complete maturation when the mushroom revives. This may also explain why the gills become thicker as the mushroom matures. [46]
Marasmius rotula is generally considered inedible, [18] but is not poisonous. The mushroom has no distinguishable odor, and its flavor varies from bland to bitter. [20] Louis Krieger, writing in National Geographic in the 1920s, noted that the mushroom was used as an addition to gravies and, when used to garnish venison, "adds the appropriate touch of the wild woodlands". [28] The fruit bodies will bioaccumulate cadmium: a study of the metal concentration of 15 wild mushroom species of India showed that M. rotula accumulated the highest concentration of that metal. [41]
A peroxidase enzyme known as MroAPO (Marasmius rotula aromatic peroxygenase) is attracting research interest for possible applications in biocatalysis. In general, enzymes that catalyze oxygen-transfer reactions are of great utility in chemical synthesis since they work selectively and under ambient conditions. Fungal peroxidases can catalyze oxidations that are difficult for the organic chemist, including those involving aromatic substrates such as aniline, 4-aminophenol , hydroquinone, resorcinol, catechol, and paracetamol. [47] The M. rotula enzyme is the first fungal peroxygenase that can be produced in high yields. It is highly stable over a wide pH range, and in a variety of organic solvents. [48] The enzyme has other potential for use as a biosensor for aromatic substances in environmental analysis and drug monitoring. [47]
Galerina marginata, known colloquially as funeral bell, deadly skullcap, autumn skullcap or deadly galerina, is a species of extremely poisonous mushroom-forming fungus in the family Hymenogastraceae of the order Agaricales. It contains the same deadly amatoxins found in the death cap. Ingestion in toxic amounts causes severe liver damage with vomiting, diarrhea, hypothermia, and eventual death if not treated rapidly. About ten poisonings have been attributed to the species now grouped as G. marginata over the last century.
Mythicomyces is a fungal genus in the family Mythicomycetaceae. A monotypic genus, it contains the single species Mythicomyces corneipes, first described by Elias Fries in 1861. The fungus produces fruit bodies with shiny yellowish-orange to tawny caps that are 1–3 cm (0.4–1.2 in) in diameter. These are supported by stems measuring 2–5.7 cm (0.8–2.2 in) long and 1–2 mm thick. A rare to uncommon species, it is found in northern temperate regions of North America and Europe, where it typically fruits in groups, in wet areas of coniferous forests. There are several species with which M. corneipes might be confused due to a comparable appearance or similar range and habitat, but microscopic characteristics can be used to reliably distinguish between them.
Mycena haematopus, commonly known as the bleeding fairy helmet, the burgundydrop bonnet, or the bleeding Mycena, is a species of fungus in the family Mycenaceae, of the order Agaricales. It is widespread and common in Europe and North America, and has also been collected in old Japan and Venezuela. It is saprotrophic—meaning that it obtains nutrients by consuming decomposing organic matter—and the fruit bodies appear in small groups or clusters on the decaying logs, trunks, and stumps of deciduous trees, particularly beech. The fungus, first described scientifically in 1799, is classified in the section Lactipedes of the genus Mycena, along with other species that produce a milky or colored latex.
Galerina sulciceps is a dangerously toxic species of fungus in the family Strophariaceae, of the order Agaricales. It is distributed in tropical Indonesia and India, but has reportedly been found fruiting in European greenhouses on occasion. More toxic than the deathcap, G. sulciceps has been shown to contain the toxins alpha- (α-), beta- (β-) and gamma- (γ-) amanitin; a series of poisonings in Indonesia in the 1930s resulted in 14 deaths from the consumption of this species. It has a typical "little brown mushroom" appearance, with few obvious external characteristics to help distinguish it from many other similar nondescript brown species. The fruit bodies of the fungus are tawny to ochre, deepening to reddish-brown at the base of the stem. The gills are well-separated, and there is no ring present on the stem.
Mycena acicula, commonly known as the orange bonnet, or the coral spring Mycena, is a species of fungus in the family Mycenaceae. It is found in Asia, the Caribbean, North America and Europe. The fruit bodies, or mushrooms, of the fungus grow on dead twigs and other woody debris of forest floors, especially along streams and other wet places. They have small orange-red caps, up to 1 cm (0.4 in) in diameter, held by slender yellowish stems up to 6 cm (2.4 in) long. The gills are pale yellow with a whitish edge. Several other Mycena species look similar, but may be distinguished by differences in size and/or microscopic characteristics. M. acicula is considered inedible because of its small size.
Atheniella adonis, which has the recommended name of scarlet bonnet in the UK, is a species of agaric in the family Cyphellaceae. Found in Asia, Europe, and North America, it produces small orangish to reddish mushrooms with caps up to 1.2 cm (0.5 in) in diameter and thin pinkish-white stems reaching 4 cm (1.6 in) long. The fungus typically grows in conifer woods and peat bogs, suggesting a preference for acidic environments. The appearance of several atypical fruitings on deciduous wood in the Netherlands in the late 1970s was attributed to increases in atmospheric pollution that raised the acidity of the wood substrate.
Mycena inclinata, commonly known as the clustered bonnet or the oak-stump bonnet cap, is a species of mushroom in the family Mycenaceae. The doubtfully edible mushroom has a reddish-brown bell-shaped cap up to 4.5 cm (1.8 in) in diameter. The thin stem is up to 9 cm (3.5 in) tall, whitish to yellow-brown at the top but progressively becoming reddish-brown towards the base in maturity, where they are covered by a yellowish mycelium that can be up to a third of the length of the stem. The gills are pale brown to pinkish, and the spore print is white. It is a widespread saprobic fungus, and has been found in Europe, North Africa, Asia, Australasia, and North America, where it grows in small groups or tufts on fallen logs and stumps, especially of oak. British mycologist E.J.H. Corner has described two varieties of the mushroom from Borneo. Lookalike species with which M. inclinata may be confused include M. galericulata and M. maculata.
Dendrocollybia is a fungal genus in the family Tricholomataceae of the order Agaricales. It is a monotypic genus, containing the single species Dendrocollybia racemosa, commonly known as the branched collybia or the branched shanklet. The somewhat rare species is found in the Northern Hemisphere, including the Pacific Northwest region of western North America, and Europe, where it is included in several Regional Red Lists. It usually grows on the decaying fruit bodies of other agarics—such as Lactarius and Russula—although the host mushrooms may be decayed to the point of being difficult to recognize.
Pholiota flammans, commonly known as the yellow pholiota, the flaming Pholiota, or the flame scalecap, is a basidiomycete agaric mushroom of the genus Pholiota. Its fruit body is golden-yellow in color throughout, while its cap and stem are covered in sharp scales. As it is a saprobic fungus, the fruit bodies typically appear in clusters on the stumps of dead coniferous trees. P. flammans is distributed throughout Europe, North America, and Asia in boreal and temperate regions. Its edibility has not been clarified.
Tulosesus impatiens is a species of fungus in the family Psathyrellaceae. First described in 1821, it has been classified variously in the genera Psathyrella, Pseudocoprinus, Coprinarius, and Coprinus, before molecular phylogenetics reaffirmed it as a Coprinellus species in 2001. The fungus is found in North America and Europe, where the mushrooms grow on the ground in deciduous forests. The fruit bodies have buff caps that are up to 4 cm (1.6 in) in diameter, held by slender whitish stems that can be up to 10 cm (3.9 in) tall. Several other Coprinopsis species that resemble C. impatiens may be distinguished by differences in appearance, habit, or spore morphology.
Palaeoagaracites is an extinct monotypic genus of gilled fungus in the order Agaricales. It contains the single species Palaeoagaracites antiquus.
Psilocybe pelliculosa is a species of fungus in the family Hymenogastraceae. The fruit bodies, or mushrooms, have a conical brownish cap up to 2 cm in diameter atop a slender stem up to 8 cm long. It has a white partial veil that does not leave a ring on the stem. American mycologist Alexander H. Smith first described the species in 1937 as a member of the genus known today as Psathyrella; it was transferred to Psilocybe by Rolf Singer in 1958.
Marasmius funalis is a species of Marasmiaceae fungus known only from Japan. The species produces small mushrooms with reddish-brown caps up to 6 millimetres (0.24 in) in diameter and dark-brown, threadlike stems of up to 50 millimetres (2.0 in) in length. The species has a number of distinctive microscopic features, including very long cystidia on the stem, visible as bristles. Described in 2002 by Haruki Takahashi, the species grows on dead wood. The closest relative of M. funalis is M. liquidambari, known from Mexico and Papua New Guinea, and it is also similar in appearance to M. hudonii and Setulipes funaliformis, the latter of which was named after M. funalis.
Marasmius capillaris is a species of agaric fungus in the family Marasmiaceae. A saprobic fungus, it produces fruit bodies (mushrooms) that grows in groups on decaying oak leaves in North America. The caps on the mushrooms are convex and then centrally depressed with radial furrows, measuring 2–15 mm (0.08–0.6 in) in diameter. The wiry, shiny stems are thin and up to 60 mm (2.4 in) long. Its spore print is white, and the spores are smooth and pip-shaped, measuring 7–11 by 3–5 μm. The mushrooms somewhat resemble Marasmius rotula, but are smaller and darker in color.
Parasola auricoma is a species of agaric fungus in the family Psathyrellaceae. First described scientifically in 1886, the species is found in Europe, Japan, and North America. The mushroom was reported in February 2019 in Colombia, in the city of Bogota by the mycologist Juan Camilo Rodriguez Martinez. The small, umbrella-shaped fruit bodies (mushrooms) of the fungus grow in grass or woodchips and are short-lived, usually collapsing with age in a few hours. The caps are up to 6 cm (2.4 in) wide, initially elliptical before flattening out, and colored reddish-brown to greyish, depending on their age and hydration. They are pleated with radial grooves extending from the center to the edge of the cap. The slender, whitish stems are up to 12 cm (4.7 in) long and a few millimeters thick. Microscopically, P. auricoma is characterized by the presence of setae in its cap cuticle. This characteristic, in addition to the relatively large, ellipsoid spores can be used to distinguish it from other morphologically similar Parasola species.
Mycena chlorophos is a species of agaric fungus in the family Mycenaceae. First described in 1860, the fungus is found in subtropical Asia, including India, Japan, Taiwan, Polynesia, Indonesia, and Sri Lanka, in Australia, and Brazil. Fruit bodies (mushrooms) have pale brownish-grey sticky caps up to 30 mm (1.2 in) in diameter atop stems 6–30 mm (0.2–1.2 in) long and up to a millimeter thick. The mushrooms are bioluminescent and emit a pale green light. Fruiting occurs in forests on fallen woody debris such as dead twigs, branches, and logs. The fungus can be made to grow and fruit in laboratory conditions, and the growth conditions affecting bioluminescence have been investigated.
Strobilurus tenacellus, commonly known as the pinecone cap, is a species of agaric fungus in the family Physalacriaceae. It is found in Asia and Europe, where it grows on the fallen cones of pine and spruce trees. The fruit bodies (mushrooms) are small, with convex to flat, reddish to brownish caps up to 15 mm (0.6 in) in diameter, set atop thin cylindrical stems up to 4–7.5 cm (1.6–3.0 in) long with a rooting base. A characteristic microscopic feature of the mushroom is the sharp, thin-walled cystidia found on the stipe, gills, and cap. The mushrooms, sometimes described as edible, are too small to be of culinary interest. The fungus releases compounds called strobilurins that suppress the growth and development of other fungi. Derivatives of these compounds are used as an important class of agricultural fungicides.
Mycena purpureofusca, commonly known as the purple edge bonnet, is a species of agaric fungus in the family Mycenaceae. First described by Charles Horton Peck in 1885, the species is found in Europe and North America, where it grows on the decaying wood and debris of conifers, including cones. Fruit bodies have conical to bell-shaped purple caps up to 2.5 cm (1 in) set atop slender stipes up to 10 cm (4 in) long. The mushroom is named for the characteristic dark greyish-purple color of its gill edges. In the field, M. purpureofusca mushrooms can usually be distinguished from similar species by characteristics such as the dark purple gill edges, the deep purple cap center, and its cartilagineous consistency. The fungus contains a laccase enzyme that has been investigated scientifically for its potential to detoxify recalcitrant industrial dyes used in textile dyeing and printing processes.
Marasmius fulvoferrugineus is a species of agaric fungus in the family Marasmiaceae. Described as new to science in 1976, it is found in the southeastern United States. The mushroom is frequently confused with Marasmius siccus, and microscopy is needed to reliably distinguish between them.
Stropharia caerulea, commonly known as the blue roundhead, is a species of mushroom forming fungus in the family Strophariaceae. It is a somewhat common species found in Europe and North America, where it grows as a saprophyte in meadows, roadsides, hedgerows, gardens, and woodchip mulch. S. caerulea was officially described to science in 1979, although it was known to be a distinct species for about two centuries before that. The scientific name Stropharia cyanea, as defined by Tuomikoski in 1953, and used by several later authors, is a synonym of S. caerulea.