Marasmius rotula

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Marasmius rotula
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Fungi
Division: Basidiomycota
Class: Agaricomycetes
Order: Agaricales
Family: Marasmiaceae
Genus: Marasmius
M. rotula
Binomial name
Marasmius rotula
(Scop.) Fr. (1838)
  • Agaricus rotula Scop. (1772)
  • Merulius collariatus With. (1796)
  • Micromphale collariatum (With.) Gray (1821)[1]
  • Androsaceus rotula (Scop.) Pat. (1887)
  • Chamaeceras rotula (Scop.) Kuntze (1898)[2]
Marasmius rotula
Edibility is inedible

Marasmius rotula is a common

Elias Fries


fruit bodies, or mushrooms, of M. rotula are characterized by their whitish, thin, and membranous caps up to 2 cm (34 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 (116 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



The species was first described by Italian mycologist

Synonyms include names derived from generic transfers to Androsaceus by Narcisse Théophile Patouillard in 1887,[7] and to Chamaeceras by Otto Kuntze in 1898;[2] 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,

rhizomorphs on the stem.[13]


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

specific epithet, which is a diminutive of rota, the Latin word for "wheel".[18]


The gills are attached to a collar encircling the stem.


fruit body is thin and membranous, measuring 3 to 20 mm (18 to 34 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 (12 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]

Microscopic characteristics

Viewed in deposit, such as with a

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]

Similar species

Marasmius capillaris grows on oak leaves.
The stem of Tetrapyrgos nigripes appears to have a powdery bloom.

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

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]

Habitat and distribution

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.

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]

Fruit bodies typically grow in clusters on woody debris.

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,

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]


organic solvents.[48] The enzyme has other potential for use as a biosensor for aromatic substances in environmental analysis and drug monitoring.[47]

See also


  1. ^ a b c Gray SF. (1821). A Natural Arrangement of British Plants. Vol. 1. London, UK: Baldwin, Cradock, and Joy. p. 622.
  2. ^ .
  3. ^ "Synonymy: Marasmius rotula (Scop.) Fr". Index Fungorum. CAB International. Retrieved 2012-06-14.
  4. ^ Scopoli JA. (1772). Flora Carniolica (in Latin). Vol. 2 (2nd ed.). Vienna, Austria: J.P. Krauss. p. 456.
  5. ^ Fries EM. (1821). Systema Mycologicum (in Latin). Vol. 1. Lundin, Sweden: ex officina Berlingiana. p. 136.
  6. ^ Fries EM. (1838). Epicrisis Systematis Mycologici (in Latin). Uppsala, Sweden: Typographia Academica. p. 385.
  7. ^ Patouillard N. (1887). Les Hyménomycètes d'Europe (in French). Paris, France: Paul Klincksieck. p. 105.
  8. .
  9. ^ Withering W. (1796). An Arrangement of British Plants. Vol. 4 (3rd ed.). Birmingham, UK: M. Swinney. p. 148.
  10. JSTOR 3755094. Archived from the original
    on 2015-09-23. Retrieved 2012-07-04.
  11. .
  12. .
  13. ^ Gilliam 1976, p. 112
  14. ^ .
  15. ^ Saccardo PA. (1887). Sylloge Fungorum (in Latin). Vol. 5. Padova, Italy: Sumptibus Auctoris. p. 541.
  16. ^ Schröter J. (1885). Kryptogamen-Flora von Schlesien (in German). Vol. 3–1(1). Lehre, Germany: Cramer. p. 558.
  17. ^ "Marasmius rotula var. phyllophila J. Schröt. 1889". MycoBank. International Mycological Association. Retrieved 2012-06-18.
  18. ^ .
  19. ^ "Recommended English Names for Fungi in the UK" (PDF). British Mycological Society. Archived from the original (PDF) on 2011-07-16.
  20. ^ .
  21. .
  22. .
  23. ^ .
  24. ^ .
  25. ^ .
  26. ^ .
  27. ^ a b c d e Gilliam 1976, pp. 122–7
  28. ^ a b Krieger LCC. (1920). "Common mushrooms of the United States". National Geographic. 37 (5): 413.
  29. ^ Gilliam 1976, p. 3
  30. ^ a b c Kuo M. (November 2004). "Marasmius rotula". Retrieved 2012-05-15.
  31. ^ Gilliam 1976, p. 121
  32. ^ .
  33. .
  34. ^ Singer R. (1989). "New taxa and new combinations of Agaricales (diagnoses fungorum novorum agaricalium IV)". Fieldiana Botany (in Latin and English) (21): 51.
  35. on 2015-09-23. Retrieved 2012-06-25.
  36. ^ Kauffman CH. (1918). The Agaricaceae of Michigan. Vol. 1. Lansing, Michigan: Wynkoop Hallenbeck Crawford Co., State Printers. p. 78.
  37. JSTOR 20791530
  38. ^ Idu M, Osemwegie OO, Onyibe HI (2008). "Checklist of flora in Edo State, Nigeria". Plant Archives. 8 (2): 539–49.
  39. JSTOR 3666575
  40. .
  41. ^ a b Das N. (2005). "Determination of lead, arsenic, cadmium, iron, copper and nickel in wild mushroom samples from South West Bengal". Mushroom Research. 14 (2): 80–3.
  42. ^ .
  43. .
  44. .
  45. .
  46. ^ .
  47. ^ .

Cited literature