 = Mycena galericulata = 
 
 Mycena galericulata is a mushroom species commonly known as the common bonnet , the <unk> <unk> , or the <unk> @-@ gill fairy helmet . The type species of the genus Mycena was first described scientifically in 1772 , but was not considered a Mycena until 1821 . It is quite variable in color , size , and shape , which makes it somewhat difficult to reliably identify in the field . The mushrooms have caps with distinct radial grooves , particularly at the margin . The cap 's color varies from grayish @-@ brown to dark brown and the shape ranges from bell @-@ like to <unk> conical to flattened with an umbo . The stem is hollow , white , tough and thin , without a ring and often roots deeply into the wood on which it grows . The gills are white to grayish or even pinkish when mature and are connected by distinct cross @-@ veins . The caps can reach 4 cm ( 1 @.@ 6 in ) in diameter , and have a <unk> odor and taste . The spore print is white and the gills are pink at maturity , which can lead to possible confusion with species of the <unk> genus . M. galericulata mushrooms grow mostly in clusters on the well @-@ decayed stumps of deciduous and coniferous trees from spring to autumn . The species can generally be considered inedible . It is common and widespread in the entire temperate zone of the Northern Hemisphere , but it has also been reported from Africa . 
 
 = = Taxonomy , classification , and naming = = 
 
 The fungus was first described scientifically as Agaricus <unk> by Italian mycologist Giovanni Antonio <unk> in 1772 , and sanctioned under this name by Elias Magnus Fries in his 1821 Systema <unk> . That same year , Samuel Frederick Gray transferred the species to the genus Mycena . <unk> for the species include Agaricus <unk> named by William Hudson in 1778 , Agaricus <unk> described by August Johann Georg Karl <unk> in 1893 , <unk> <unk> by Franklin Sumner <unk> in 1909 , and <unk> <unk> by William <unk> <unk> in 1916 . 
 Mycena galericulata is the type species of the genus Mycena . It is classified in section Mycena of Mycena in the <unk> scheme of Rudolph Arnold <unk> <unk> . In the older ( 1947 ) classification of Alexander H. Smith , he placed it in the subgenus <unk> , section <unk> — " a most <unk> series of blackish , brown , gray , bluish @-@ gray , or brownish @-@ gray species mostly with ascending gills and generally large to moderate stature . " 
 The specific epithet galericulata is derived from the Latin <unk> , and means " with a small hat " . Gray called it the " <unk> high @-@ stool " . It is commonly known as the " common bonnet " , the " <unk> <unk> " , or the " <unk> @-@ gill fairy helmet " . 
 
 = = Description = = 
 
 The cap of M. galericulata is roughly conical when young , and eventually becomes broadly bell @-@ shaped or with a broad umbo that can reach diameters of 2 – 4 cm ( 0 @.@ 8 – 1 @.@ 6 in ) . The cap margin is initially somewhat curved inward , but soon <unk> out or even becomes <unk> , and often splits <unk> in age . The surface has radial grooves that extend nearly to the center , and feels <unk> but not sticky . The color is somewhat buff @-@ brown on the margin , and fades gradually to pale dirty tan to dirty <unk> @-@ brown . The flesh is thick in the center of the cap and tapers evenly to the margin , and is watery gray , with a cartilage @-@ like texture . The odor and taste are <unk> to strongly farinaceous ( similar to the smell of <unk> ground flour ) , to <unk> @-@ like . 
 The gills are narrowly attached ( <unk> ) to broadly attached or <unk> . The gill spacing ranges from close to somewhat distantly spaced , with 26 – 36 gills reaching the stem ; there are additionally three or four tiers of <unk> ( short gills that do not extend completely from the cap margin to the stem ) . The gills are strongly <unk> ( possessing cross @-@ veins ) , moderately broad ( 5 – 7 mm ) , white or grayish white , soon flushed with pale pink , with even edges . The stem is 5 – 9 cm ( 2 @.@ 0 – 3 @.@ 5 in ) long , 2 – 4 mm ( 0 @.@ 08 – 0 @.@ 16 in ) thick , equal in width throughout , and with a <unk> texture . It is hollow , not hairy , either smooth or twisted with longitudinal <unk> , often with a long <unk> ( a subterranean <unk> of the stem ) at the base . The stem color is pale grayish @-@ white on the upper portion , and pale grayish @-@ black below ; the base becomes somewhat dirty brown in age , but does not develop reddish stains . 
 Mycena galericulata produces a white spore print . The spores are ellipsoid , 8 – 10 by 5 @.@ 5 – 7 μm , and amyloid — which means they will turn blue @-@ black to black when stained with Melzer 's reagent . The basidia ( spore @-@ bearing cells ) have stout sterigmata , and measure 34 – 40 by 7 – 9 μm . They may be either two @-@ spored or four @-@ spored . There are numerous club @-@ shaped to rounded cheilocystidia ( cystidia on the gill edge ) , that measure 32 – 40 by 8 – 12 μm ; their <unk> or the entire enlarged portion bear <unk> projections that become increasingly elongated and branched in age . There are no <unk> ( cystidia on the gill face ) . The gill tissue has a very thin <unk> , under which is a narrow <unk> , while the remainder of the tissue comprises densely matted <unk> of mycelia , and stains deep <unk> @-@ brown in iodine . Clamp connections are present in the hyphae of the four @-@ spored forms . 
 
 = = = Edibility = = = 
 
 Opinions on the edibility of the mushroom vary . One source considers them to have a " delicate flavor and texture " , and suggests that they are good when " <unk> gently in their own juice and then <unk> with salt , <unk> and butter . " Others list the species as inedible , and notes that they have a " <unk> rancid " smell , and with a taste ranging from rancid to farinaceous . Another says " unknown , but not recommended . " At any rate , the species falls into the general category of brownish <unk> that are generally <unk> as food due to their small size and delicate consistency . 
 
 = = = Similar species = = = 
 
 The winter bonnet ( M. <unk> ) is a northern European species that is much smaller ( cap diameter up to 2 @.@ 6 cm ( 1 @.@ 0 in ) across ) and has a brown cap , and has ragged hairs at the base . It generally appears in late autumn to early winter on the stumps of deciduous trees , especially beech . It has <unk> @-@ shaped spores that are smaller than M. galericulata , around 4 @.@ 5 – 5 @.@ 5 by 2 @.@ 5 – 2 @.@ 8 µm . M. <unk> develops pink stains on its gills as it matures ; its spores are 7 – 9 by 4 – 5 μm . Another similar species is M. <unk> , which can be distinguished by gills bearing reddish spots , which may become entirely red with age . It also has whitish , slender , threadlike <unk> on the stalk . M. <unk> is thinner , and more fragile . Another Mycena that grows in clusters on decaying <unk> is M. <unk> , but this species has a <unk> @-@ brown cap with a <unk> margin , and a stem that <unk> reddish @-@ brown juice when injured . M. <unk> closely resembles M. galericulata , but can be distinguished microscopically by the presence of both smooth and <unk> cystidia ( bearing finger @-@ like projections ) . 
 
 = = Ecology , habitat and distribution = = 
 
 Mycena galericulata is saprobic , and grows on decaying hardwood and <unk> sticks , chips , logs , and stumps . It can also grow from submerged wood , which may give it a terrestrial appearance . It typically grows in small clusters or sometimes singly . The fungus fruits from late spring to early winter . A study of litter @-@ decomposing fungi in a coniferous forest in Finland showed that M. galericulata produces extracellular <unk> enzymes in the <unk> and <unk> soil , including β @-@ <unk> , β @-@ <unk> , α @-@ <unk> , <unk> esterase and <unk> . The enzymes form complexes with <unk> and organic particles in the soil and break down ( <unk> ) <unk> such as <unk> , <unk> , and <unk> , which contributes to the cycling of carbon and nutrients . The presence of lead contamination in the soil decreases both the growth and the extracellular <unk> enzyme activity of M. galericulata . 
 Mycena galericulata is a very common and widely distributed species , found throughout the entire temperate zone of the Northern Hemisphere . In the United States , it occurs throughout eastern North America and also along the Pacific Coast . It has also been collected in Edo State , Nigeria . Although the mushroom has occasionally been reported from Australia , these collections are probably based on <unk> , and " Australian records of Mycena galericulata are best regarded as erroneous " . 
 
 = = = Cited literature = = = 
 
 Smith AH . ( 1947 ) . North American species of Mycena . Ann Arbor , Michigan : University of Michigan Press . 
 
 