A mushroom is an above ground fruiting body
(that is spore-producing structure) of a fungus, having a shaft
and a cap; and by extension, the entire fungus producing the
fruiting body of such appearance, the former consisting of a
network (called the mycelium) of filaments or hyphae. In a much
broader sense, mushroom is applied to any visible fungus, or
especially the fruiting body of any fungus. The technical term
for the spore-producing structure of "true" mushrooms is the
basidiocarp.
Identifying mushrooms requires a basic understanding of their
macroscopic structure. A "typical" mushroom consists of a cap or
pileus supported on a stem or stipe. Both can have a variety of
shapes and be ornamented in various ways. The underside of the
cap (in agarics) is fitted with gills or lamellae where the
actual spores are produced. How the gills are attached is
another important characteristic used in identification. In the
boletes, the gills are replaced by small openings called pores.
Bracket fungi essentially lack a stipe, and the cap is attached
like a bracket to the substratum, usually a log or tree trunk.
Some bracket fungi have gills, others have pores.
In general, identification to genus can be accomplished in the
field using a local mushroom guide. Identification to species
requires more work. Realize that a mushroom develops from a
young bud into a mature structure and only the latter can
provide certain identification of the species. Examination of
mature spores, or at least knowing their color, is often
essential. And to this end, a common method used to assist in
identification is the spore print.
There are thousands of regularly harvested edible fungi in the
world, in addition to literally hundreds of thousands of other
edible species. Some species are highly priced because they
cannot be cultivated and are often harvested from natural
settings.
