Poisonous mushroom in the context of "Ingestion"

A mushroom is the fleshy, spore-bearing fruiting body of a fungus, typically produced above ground on soil or another food source. A toadstool generally refers to a poisonous mushroom.

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 (Basidiomycota, Agaricomycetes) that have a stem (stipe), a cap (pileus), and gills (lamellae, sing. lamella) on the underside of the cap. "Mushroom" also describes a variety of other gilled fungi, with or without stems; therefore the term is used to describe the fleshy fruiting bodies of some Ascomycota. The gills produce microscopic spores which help the fungus spread across the ground or its occupant surface.

Edible mushrooms are the fleshy fruit bodies of numerous species of properly identified and prepared fungi. Edibility may be defined by criteria including their palatability and absence of dangerous mycotoxins. Edible mushrooms are consumed for their nutritional and culinary value, often either being cultivated or harvested wild. Easily cultivated and common wild mushrooms are often available in markets; those that are more difficult to obtain may be collected on a smaller scale.

To ensure safety, wild mushrooms must be correctly identified before their edibility can be assumed. Deadly poisonous mushrooms that are frequently confused with edible mushrooms include several species of the genus Amanita, particularly A. phalloides (the death cap). Some mushrooms that are edible for most people can cause allergic reactions in others; old or improperly stored specimens can cause food poisoning. Additionally, mushrooms can absorb chemicals from polluted locations, accumulating pollutants and potentially lethal heavy metals.

Entoloma sinuatum (commonly known as the livid entoloma, livid agaric, livid pinkgill, leaden entoloma, and lead poisoner) is a poisonous mushroom found across Europe and North America. Some guidebooks refer to it by its older scientific names of Entoloma lividum or Rhodophyllus sinuatus. The largest mushroom of the genus of pink-spored fungi known as Entoloma, it is also the type species. Appearing in late summer and autumn, fruit bodies are found in deciduous woodlands on clay or chalky soils, or nearby parklands, sometimes in the form of fairy rings. Solid in shape, they resemble members of the genus Tricholoma. The ivory to light grey-brown cap is up to 20 cm (7.9 in) across with a margin that is rolled inward. The sinuate gills are pale and often yellowish, becoming pink as the spores develop. The thick whitish stem has no ring.

When young, it may be mistaken for the edible St George's mushroom (Calocybe gambosa) or the miller (Clitopilus prunulus). It has been responsible for many cases of mushroom poisoning in Europe. E. sinuatum causes primarily gastrointestinal problems that, though not generally life-threatening, have been described as highly unpleasant. Delirium and depression are uncommon sequelae. It is generally not considered to be lethal, although one source has reported deaths from the consumption of this mushroom.

In mycology, a volva is a cup-like structure at the base of a mushroom that is a remnant of the universal veil, or the remains of the peridium that encloses the immature fruit bodies of gasteroid fungi. This macrofeature is important in wild mushroom identification because it is an easily observed, taxonomically significant feature that frequently signifies a member of Amanitaceae. This has particular importance due to the disproportionately high number of deadly poisonous species contained within that family.

A mushroom's volva is often partially or completely buried in the ground, and therefore care must be taken to check for its presence when identifying mushrooms. Cutting or pulling mushrooms and attempting to identify them later without having noted this feature could be a fatal error.