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''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 wide that are sunken in the center, and pleated with scalloped margins. The slender and wiry black hollow stems measure up to long by 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. Unlike other mushrooms known to release 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. Although ''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. == Taxonomy == The species was first described by Italian mycologist Giovanni Antonio Scopoli as ''Agaricus rotula'' in 1772.〔 In 1821 Elias Magnus Fries redescribed the mushroom in ''Systema Mycologicum'',〔 and later transferred it to ''Marasmius'' in his 1838 ''Epicrisis Systematis Mycologici''.〔 Synonyms include names derived from generic transfers to ''Androsaceus'' by Narcisse Théophile Patouillard in 1887,〔 and to ''Chamaeceras'' by Otto Kuntze in 1898;〔 both of these genera are now obsolete and have since been sunk back into ''Marasmius''.〔 In his 1821 ''A Natural Arrangement of British Plants'', Samuel Frederick Gray introduced the generic name ''Micromphale'', including the species ''Micromphale collariatum'',〔 which was based on William Withering's 1796 ''Merulius collariatus''.〔 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.〔 The generic name ''Marasmius'', with ''M. rotula'' as the lectotype species, was later conserved at the 1954 Paris Congress on Botanical Nomenclature.〔〔 ''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.〔 Several varieties of ''M. rotula'' have been described. Miles Berkeley and Moses Ashley Curtis named var. ''fuscus'' in 1869 for its brown cap.〔 In 1887 Pier Andrea Saccardo described var. ''microcephalus'' from Italy, with caps half the normal size.〔 It is now understood, however, that fruit body morphology is variable and dependent upon environmental conditions. Joseph Schröter described var. ''phyllophyla'' in 1889,〔 but that taxon is now treated as ''Marasmius bulliardii''.〔 ''Marasmius rotula'' is commonly known as the "pinwheel mushroom", the "pinwheel Marasmius",〔 the "collared parachute",〔 or the "horse hair fungus".〔 This latter name is shared with other ''Marasmius'' species, including ''M. androsaceus''〔 and ''M. crinis-equi''.〔 Gray called it the "collared dimple-stool".〔 The name "little wheel fungus" is suggestive of the collar to which the gills are attached like the spokes of a wheel,〔 like the specific epithet, which is a diminutive of ''rota'', the Latin word for "wheel".〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Marasmius rotula」の詳細全文を読む スポンサード リンク
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