Panaeolus acuminatus, also known as Panaeolus rickenii is a common little brown mushroom

Mushroom

A mushroom is the fleshy, spore-bearing fruiting body of a fungus, typically produced above ground on soil or on its food source. The standard for the name "mushroom" is the cultivated white button mushroom, Agaricus bisporus; hence the word "mushroom" is most often applied to those fungi that...

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This species contains small amounts of serotonin

Serotonin

Serotonin or 5-hydroxytryptamine is a monoamine neurotransmitter. Biochemically derived from tryptophan, serotonin is primarily found in the gastrointestinal tract, platelets, and in the central nervous system of animals including humans...

, 5-HTP, and tryptophan

Tryptophan

Tryptophan is one of the 20 standard amino acids, as well as an essential amino acid in the human diet. It is encoded in the standard genetic code as the codon UGG...

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Description

This is a little brown mushroom that grows on dung

Manure

Manure is organic matter used as organic fertilizer in agriculture. Manures contribute to the fertility of the soil by adding organic matter and nutrients, such as nitrogen, that are trapped by bacteria in the soil...

 and has black spore

Spore

In biology, a spore is a reproductive structure that is adapted for dispersal and surviving for extended periods of time in unfavorable conditions. Spores form part of the life cycles of many bacteria, plants, algae, fungi and some protozoa. According to scientist Dr...

s. It has a cap that is less than 4 cm across, hygrophanous

Hygrophanous

The adjective hygrophanous refers to the color change of mushroom tissue as it loses or absorbs water, which causes the pileipellis to become more transparent when wet and opaque when dry....

, conic to campanulate to plane, usually with an umbo

Umbo

Umbo may refer to:*A shield boss* umbo , at the top of some mushrooms*The Umbo of tympanic membrane - a part of the human body*Umbo is the part of a Bivalve shell which was formed when the animal was a juvenile...

. The gills are dark purplish black, crowded, with several tiers of intermediate gills. The spores are (11) 13 - 15 (17) x 9 - 11 (12) x (6.5) 7 - 8 (9) micrometers, smooth, black, and shaped like lemons. Cheilocystidia present.

Habitat and distribution

Panaeolus acuminatus is a mushroom that grows in grass

Grass

Grasses, or more technically graminoids, are monocotyledonous, usually herbaceous plants with narrow leaves growing from the base. They include the "true grasses", of the Poaceae family, as well as the sedges and the rushes . The true grasses include cereals, bamboo and the grasses of lawns ...

 and in dung. It has been found throughout North America

North America

North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...

 and Europe

Europe

Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...

and is very widely distributed.

External links

• Mushroom Observer - Panaeolus acuminatus
• Mushroom Observer - Panaeolus acuminatus