''Leucocoprinus straminellus'' is a species of
mushroom
A mushroom or toadstool is the fleshy, spore-bearing fruiting body of a fungus, typically produced above ground, on soil, or on its food source. ''Toadstool'' generally denotes one poisonous to humans.
The standard for the name "mushroom" is ...
producing
fungus
A fungus ( : fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, separately from t ...
in the family
Agaricaceae
The Agaricaceae are a family of basidiomycete fungi and include the genus ''Agaricus'', as well as basidiomycetes previously classified in the families Tulostomataceae, Lepiotaceae, and Lycoperdaceae.
Taxonomy
The family Agaricaceae was publishe ...
. Like other ''
Leucocoprinus
''Leucocoprinus'' is a genus of fungi in the family Agaricaceae. Its best-known member is the distinctive yellow mushroom '' Leucocoprinus birnbaumii'', which is found in plant pots and greenhouses worldwide. The type species is '' Leucocoprinus ...
'' species it may have originated in a tropical climate but now finds a home in plant pots, greenhouses and compost piles in many countries. ''Leucocoprinus straminellus'' is described as being similar to the more commonly known ''
Leucocoprinus birnbaumii
''Leucocoprinus birnbaumii'' is a species of gilled mushroom in the family Agaricaceae. It is common in the tropics and subtropics. However, in temperate regions, it frequently occurs in greenhouses and flowerpots, hence its common names of flowe ...
'' but it is smaller and a lighter shade of yellow with smaller spores that lack a germ pore. It is also described as being superficially similar to ''
Leucocoprinus fragilissimus'' but slightly more robust with flesh that is less translucent.
Taxonomy
It was first
described in 1865 by the Italian botanist
Francesco Baglietto who classified it as ''Agaricus straminellus''.
In 1887 the Italian mycologist
Pier Andrea Saccardo
Pier Andrea Saccardo (23 April 1845 in Treviso, Treviso – 12 February 1920 in Padua) was an Italian botanist and mycologist.
Life
Saccardo studied at the Lyceum in Venice, and then at the Technical Institute of the University of Padua wher ...
classified it as ''Lepiota straminella.''
It was reclassified as ''Leucocoprinus straminellus'' by the Italian mycologists
Roberto Narducci and
Vincenzo Caroti in 1995. However it is still sometimes referred to by its former name ''Leucocoprinus denudatus'' which it acquired in 1951 when classified by the German mycologist
Rolf Singer.
In 1999 the variant ''Leucocoprinus straminellus var. albus'' was described by the mycologists
Vincenzo Migliozzi &
Marcello Rava. This is now considered a synonym.
Description
''Leucocoprinus straminellus'' is a small dapperling mushroom with thin whitish to pale yellow flesh.
Cap: 1.5-2.5 cm wide, ovoid to campanulate (bell shaped) maturing to convex or almost flat with age but retaining the
umbo. The surface is whitish yellow with a darker yellow centre and the margins are striated. Stem: 2.4–5 cm tall tapering upwards from a swollen base. The stem ring is located towards the top of the stem (median-superior) but quickly disappears. Gills: Free with a collar, distant and white-cream. Spore print: White. Spores: Ellipsoid to spherical and smooth. Dextrinoid. 5-6 x 4-4.5 μm. Taste: Indistinct. Smell: Indistinct.
The description of ''Leucocoprinus denudatus''
(now considered a synonym) from 1981 includes the following details:
Cap: 1.6-2.4 cm wide. Ovoid to campanulate or hemispheric and expanding with age to become convex or flat. Pale greenish-yellow in colour with the centre presenting with a deeper colour. The cap edges are paler and have striations. The centre of the cap is velvety in texture whilst the rest of the cap is covered in a fine powdery substance (pruinose) when examined under a lens. Gills: Crowded and free, tinted pale yellow or the same colour as the cap. Stem: 1.5-4.5 cm long and 2-3mm thick at the top, 4-6mm at the base. Paler yellow than the cap with a small, membranous stem ring that is high up (superior). The stem texture is smooth or very finely pruinose when examined with a lens and the base is often covered with soil. Spores: Globose to subglobose to broadly ovoid, with a minute apiculus, lacking a
germ pore
A germ pore is a small pore in the outer wall of a fungal spore through which the germ tube exits upon germination. It can be apical or eccentric in its location, and, on light microscopy, may be visualized as a lighter coloured area on the cell ...
. 3.6-4.5 x (3.6) 4-4.8 μm and rarely up to 6-8 x 5.2μm. Pale yellow to rust yellow in
Melzer's reagent
Melzer's reagent (also known as Melzer's iodine reagent, Melzer's solution or informally as Melzer's) is a chemical reagent used by mycologists to assist with the identification of fungi, and by phytopathologists for fungi that are plant pathogens ...
. Basidia: 24-36 x 5-8μm, narrowly clavate to nearly cylindrical.
Dried specimens present with a brown umbo whilst the rest of the cap is yellow however dry immature specimens may develop brownish tones on the rest of the cap.
Due to the similarities with ''Leucocoprinus flavescens'' these species may often be confused resulting in inconsistencies in descriptions.
Habitat and distribution
Specimens studied in 1981 where found in June at the University of Michigan Botanical Garden. They were growing in dense clusters. This was the first observation of the species in North America but it is more commonly found in Europe.
Similar species
''
Leucocoprinus flavescens'' is described similarly with some sources suggesting they may be synonymous although they appear to have different sized spores and different coloured cap centres.
References
{{Taxonbar, from=Q10560188
Agaricaceae
Leucocoprinus
Fungi described in 1865
Taxa named by Francesco Baglietto