''Cystolepiota potassiovirens'' 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 t ...

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 th ...

in the family Agaricaceae.

Taxonomy

It was described in 1989 by the German mycologist

Rolf Singer Rolf Singer (June 23, 1906 – January 18, 1994) was a Germany, German-born mycologist and one of the most important Taxonomy (biology), taxonomists of gilled mushrooms (agarics) in the 20th century. After receiving his Ph.D. at the University ...

who classified it as ''Cystolepiota potassiovirens.''

Description

''Cystolepiota potassiovirens'' is a very small brownish mushroom with brown flesh. Cap: 1cm wide and convex with a small umbo. The surface is brown to dark brown with a pale orange umbo covered with furfuraceous (bran like) scales. Gills: Free, dark brown and close to crowded. They have a slight ventricose bulge in the middle. Stem: 1.7cm tall and 0.8-1mm thick and subequal. The surface is dark brown with a pruinose (powdery) coating. Spores: Ellipsoidal without a germ pore, hyaline, non-amyloid but greenish in KOH. 3.3-4 x 2.5-3μm. Basidia: 15-21 x 5 μm. Four spored. Smell: Indistinct.

Etymology

The specific epithet ''potassiovirens'' derives from the Latin ''potassio'' meaning potassium and ''virens'' meaning green. This is in reference to the green colouration the spores develop in

Potassium Hydroxide Potassium hydroxide is an inorganic compound with the formula K OH, and is commonly called caustic potash. Along with sodium hydroxide (NaOH), KOH is a prototypical strong base. It has many industrial and niche applications, most of which exp ...

(KOH).

Habitat and distribution

The specimens studied by Singer were found growing solitary or gregariously on the ground in the tropical forests of Brazil, 30km North of

Manaus Manaus () is the capital and largest city of the Brazilian state of Amazonas. It is the seventh-largest city in Brazil, with an estimated 2020 population of 2,219,580 distributed over a land area of about . Located at the east center of the s ...

References

{{Taxonbar, from=Q107611716 Agaricaceae Fungi described in 1989 Fungi of South America Taxa named by Rolf Singer Fungus species