is the fleshy, spore-bearing fruiting body of a fungus, typically
produced above ground on soil or on its food source. Like all fungi,
mushrooms are not plants and do not undergo photosynthesis. 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) or pores
on the underside of the cap.
"Mushroom" describes a variety of gilled fungi, with or without stems,
and the term is used even more generally, to describe both the fleshy
fruiting bodies of some Ascomycota and the woody or leathery fruiting
bodies of some Basidiomycota, depending upon the context of the word.
deviating from the standard morphology usually have more specific
names, such as "puffball", "stinkhorn", and "morel", and gilled
mushrooms themselves are often called "agarics" in reference to their
similarity to Agaricus or their place Agaricales. By extension, the
term "mushroom" can also designate the entire fungus when in culture or
the thallus (called a mycelium) of species forming the fruiting bodies
called mushrooms, or the species itself.