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 fungi (
Basidiomycota,
Agaricomycetes) that have a
stem (
stipe), a cap (
pileus), and gills (lamellae, sing.
lamella) on the underside of the cap just as do store-bought white mushrooms. However, "mushroom" can also refer to a wide 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. Forms deviating from the standard form 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 placement in the order
Agaricales. By extension, "mushroom" can also designate the entire fungus when in culture or the
thallus (called a
mycelium) of species forming the fruiting bodies called mushrooms.
Contents
1 Identification2 Classification3 Mushroom vs. toadstool4 Growth rates5 Size and age6 Human use6.1 Edible mushrooms6.2 Toxic mushrooms6.3 Psychoactive mushrooms6.4 Medicinal mushrooms6.5 Other uses7 References8 Further reading9 External links9.1 Research relatedIdentification
Identifying mushrooms requires a basic understanding of their
macroscopic structure. Most are
Basidiomycetes and gilled. Their spores, called
basidiospores, are produced on the gills and fall in a fine rain of powder from under the caps as a result. At the microscopic level the basidiospores are shot off of
basidia and then fall between the gills in the dead air space. As a result, for most mushrooms, if the cap is cut off and placed gill-side-down overnight, a powdery impression reflecting the shape of the gills (or pores, or spines, etc.) is formed (when the fruitbody is sporulating). The color of the powdery print, called a
spore print, is used to help classify mushrooms and can help to identify them. Spore print colors include white (most common), brown, black, purple-brown, pink, yellow, and cream, but almost never blue, green, or red.
While modern identification of mushrooms is quickly becoming molecular, the standard methods for identification are still used by most and have developed into a fine art harking back to
medieval times and the
Victorian era, combined with microscopic examination. The presence of juices upon breaking, bruising reactions, odors, tastes, shades of color, habitat, habit, and season are all considered by mycologists, amateur and professional alike. Tasting and smelling mushrooms carries its own hazards because of poisons and
allergens. Chemical
tests are also used for some genera.
In general, identification to
genus can often be accomplished in the field using a local mushroom guide. Identification to
species, however, requires more effort; one must remember that a mushroom develops from a button stage into a mature structure, and only the latter can provide certain characteristics needed for the identification of the species. However, over-mature specimens lose features and cease producing spores. Many novices have mistaken humid water marks on paper for white spore prints, or discolored paper from oozing liquids on lamella edges for colored spored prints.
Classification
The genus Trichaptum, an example of a
polypore, a mushroom without a stalk, fruiting on a log
Main articles:
Sporocarp (fungi),
Basidiocarp, and
AscocarpTypical mushrooms are the fruitbodies of members of the order
Agaricales, whose type genus is
Agaricus and type species is the field mushroom,
Agaricus campestris. However, in modern molecularly defined classifications, not all members of the order Agaricales produce mushroom fruitbodies, and many other gilled fungi, collectively called mushrooms, occur in other orders in the class
Agaricomycetes. For example,
chanterelles are in the
Cantharellales, false chanterelles like
Gomphus are in the
Gomphales, milk mushrooms (
Lactarius) and russulas (
Russula) as well as
Lentinellus are in the
Russulales, while the tough leathery genera
Lentinus and
Panus are among the
Polyporales, but
Neolentinus is in the
Gloeophyllales, and the little pin-mushroom genus,
Rickenella, along with similar genera, are in the
Hymenochaetales.
Within the main body of mushrooms, in the
Agaricales, are common fungi like the common fairy-ring mushroom (
Marasmius oreades),
shiitake,
enoki,
oyster mushrooms,
fly agarics, and other
amanitas,
magic mushrooms like species of
Psilocybe,
paddy straw mushrooms,
shaggy manes, etc.
An atypical mushroom is the
Lobster mushroom, which is a deformed, cooked-lobster-colored
parasitized fruitbody of a
Russula or
Lactarius colored and deformed by the mycoparasitic
Ascomycete Hypomyces lactifluorum.
[1]Other mushrooms are non-gilled, and then the term "mushroom" is loosely used, so that it is difficult to give a full account of their classifications. Some have pores underneath (and are usually called
boletes), others have spines, such as the
hedgehog mushroom and other
tooth fungi, and so on. "Mushroom" has been used for
polypores,
puffballs,
jelly fungi,
coral fungi,
bracket fungi,
stinkhorns, and
cup fungi. Thus, the term mushroom is more one of common application to
macroscopic fungal fruiting bodies than one having precise
taxonomic meaning. There are approximately 14,000 described species of mushrooms.
[2]The relative sizes of the cap (
pileus) and stalk (
stipe) vary widely. Shown here is a species of Macrolepiota.
Mushroom vs. toadstool
The terms "mushroom" and "toadstool" go back centuries and were never precisely defined, nor was there consensus on application. The term "toadstool" was often but not exclusively applied to poisonous mushrooms or to those that have the classic umbrella-like cap-and-stem form. Between 1400 and 1600 A.D., the terms tadstoles, frogstooles, frogge stoles, tadstooles, tode stoles, toodys hatte, paddockstool, puddockstool, paddocstol, toadstoole, and paddockstooles sometimes were used synonymously with mushrom, mushrum, muscheron, mousheroms, mussheron, or musserouns.
[3] The term "mushroom" and its variations may have been derived from the French word mousseron in reference to moss (mousse). There may have been a direct connection to
toads (in reference to poisonous properties) for toadstools. However, there is no clear-cut delineation between edible and poisonous fungi, so that a "mushroom" may be edible, poisonous, or unpalatable. The term "toadstool" is nowadays used in storytelling when referring to poisonous or suspect mushrooms. The classic example of a toadstool is
Amanita muscaria.
Growth rates
Many species of mushrooms seemingly appear overnight, growing or expanding rapidly. This phenomenon is the source of several common expressions in the
English language including "to mushroom" or "mushrooming" (expanding rapidly in size or scope) and "to pop up like a mushroom" (to appear unexpectedly and quickly). In actuality all species of mushrooms take several days to form primordial mushroom fruitbodies, though they do expand rapidly by the absorption of fluids. The
cultivated mushroom as well as the common
field mushroom initially form a minute
fruiting body, referred to as the pin stage because of their small size. Slightly expanded they are called buttons, once again because of the relative size and shape. Once such stages are formed, the mushroom can rapidly pull in water from its
mycelium and expand, mainly by inflating preformed
cells that took several days to form in the
primordia. Similarly, there are even more ephemeral mushrooms, like
Parasola plicatilis (
[1] formerly
Coprinus plicatlis), that literally appear overnight and may disappear by late afternoon on a hot day after rainfall. The primordia form at ground level in lawns in humid spaces under the
thatch and after heavy rainfall or in
dewy conditions balloon to full size in a few hours, release spores, and then collapse. They "mushroom" to full size. The
slang term "mushrooms" is a gang-related term for victims accidentally shot as collateral damage simply because they popped up suddenly, as do fungal mushrooms.
[4]Yellow, flower pot mushrooms (
Leucocoprinus birnbaumii) at various states of development
Not all mushrooms expand overnight; some grow very slowly and add tissue to their fruitbodies by growing from the edges of the colony or by inserting
hyphae.
Size and age
Though mushroom fruiting bodies are short-lived, the underlying
mycelial colony can itself be long-lived and massive. A colony of
Armillaria ostoyae in
Malheur National Forest in the
United States is estimated to be 2,400 years old, possibly older, and spans an estimated 2,200 acres. Most of the fungus is underground and in decaying wood or dying tree roots in the form of white mycelia combined with black shoelace-like
rhizomorphs that bridge colonized separated woody substrates.
Human use
The
button mushroom (Agaricus bisporus), one of the most widely cultivated mushrooms in the world.
Further information:
EthnomycologyEdible mushrooms
Main articles:
Edible mushrooms,
Mushroom hunting, and
FungicultureEdible mushrooms are used extensively in
cooking, in many
cuisines (notably
Chinese,
European, and
Japanese). Though mushrooms are commonly thought to have little nutritional value, many species are high in fiber and provide vitamins such as
thiamine,
riboflavin,
niacin,
biotin,
cobalamins,
ascorbic acid. Though not normally a significant source of
vitamin D, some mushrooms can become significant sources after exposure to
ultraviolet light, though this also darkens their skin.
[6] Mushrooms are also a source of some minerals, including
iron,
selenium,
potassium and
phosphorus.
Most mushrooms that are sold in supermarkets have been commercially grown on
mushroom farms. The most popular of these,
Agaricus bisporus, is safe for most people to eat because it is grown in controlled, sterilized environments, though some individuals do not tolerate it well. Several varieties of A. bisporus are grown commercially, including whites,
crimini, and
portabello. Other cultivated species now available at many grocers include
shiitake,
maitake or
hen-of-the-woods,
oyster, and
enoki.
Mushroom and
Truffle output in 2005
There are a number of species of mushroom that are
poisonous, and although some resemble certain edible species, eating them could be fatal. Eating mushrooms gathered in the wild is risky and should not be undertaken by individuals not knowledgeable in mushroom identification, unless the individuals limit themselves to a relatively small number of good edible species that are visually distinctive. More generally, and particularly with gilled mushrooms, separating edible from poisonous species requires meticulous attention to detail; there is no single trait by which all toxic mushrooms can be identified, nor one by which all edible mushrooms can be identified.
People who collect mushrooms for consumption are known as mycophagists, and the act of collecting them for such is known as
mushroom hunting, or simply "mushrooming".
Toxic mushrooms
Main article:
Mushroom poisoningThe
Panther cap (Amanita pantherina), a toxic mushroom
Of central interest with respect to the chemical properties of mushrooms is the fact that many species produce
secondary metabolites that render them toxic, mind-altering, or even
bioluminescent. Though there are only a small number of
deadly species, several have particularly severe and unpleasant symptoms. Toxicity likely plays a role in protecting the function of the basidiocarp: the mycelium has expended considerable energy and protoplasmic material to develop a structure to efficiently distribute its spores. One defense against consumption and premature destruction is the evolution of chemicals that render the mushroom inedible, either causing the consumer to vomit (see
emetics) the meal or avoid consumption altogether.
Psychoactive mushrooms
Main article:
Psychedelic mushroomsPsilocybin mushrooms possess
psychedelic properties. They are commonly known as "magic mushrooms" "mush" or "shrooms" and are available in
smart shops in many parts of the world, though some countries have outlawed their sale. A number of other mushrooms are eaten for their psychoactive effects, such as
fly agaric, which is used for
shamanic purposes by tribes in northeast
Siberia, Russia. They have also been used in the West to potentiate, or increase, religious experiences. Because of their psychoactive properties, some mushrooms have played a role in native medicine, where they have been used in an attempt to effect mental and physical healing, and to facilitate visionary states. One such ritual is the
Velada ceremony. A practitioner of traditional mushroom use is the
shaman and
curandera (priest-healer)
María Sabina.
Medicinal mushrooms
Currently, many species of mushrooms and fungi used in
folk medicine for thousands of years are under intense study by
ethnobotanists and medical researchers.
Maitake,
shiitake,
chaga, and
reishi are prominent among those being researched for their potential anti-
cancer, anti-
viral, or immunity-enhancing properties.
Psilocybin, originally an extract of certain psychedelic mushrooms, is being studied for its ability to help people suffering from mental disease, such as
obsessive-compulsive disorder. Minute amounts have been reported to stop
cluster and
migraine headaches.
[2]Other uses
Mushrooms can be used for
dyeing wool and other natural fibers. The
chromophores of mushrooms are organic compounds and produce strong and vivid colors, and all colors of the spectrum can be achieved with mushroom dyes. Before the invention of synthetic
dyes mushrooms were the primary source of textile dyes. This technique has survived in Finland, and many
Middle Ages re-enactors have revived the skill.[
citation needed] Some fungi, types of
polypores loosely called mushrooms, have been used as fire starters (known as
tinder fungi).
Ötzi the Iceman was found carrying such fungi. Mushrooms and other
fungi will likely play an increasingly important role in the development of effective biological remediation and filtration technologies.
The US Patent and Trademark office can be searched for patents related to the latest developments in
mycoremediation and
mycofiltration.
