Open main menu

Fungi

Karl Johanssvamp, Iduns kokbok.png

A fungus is any member of a large group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. The Fungi are classified as a kingdom that is separate from plants and animals. The discipline of biology devoted to the study of fungi is known as mycology, which is often regarded as a branch of botany, even though genetic studies have shown that fungi are more closely related to animals than to plants. Fungi reproduce via spores, which are often produced on specialized structures or in fruiting bodies, such as the head of a mushroom. Abundant worldwide, most fungi are inconspicuous to the naked eye because of the small size of their structures, and their cryptic lifestyles in soil, on dead matter, and as symbionts of plants, animals, or other fungi. Fungi perform an essential role in the decomposition of organic matter and have fundamental roles in nutrient cycling and exchange. They have long been used as a direct source of food, such as mushrooms and truffles, as a leavening agent for bread, and in fermentation of various food products, such as wine, beer, and soy sauce. Since the 1940s, fungi have been used for the production of antibiotics, and, more recently, various enzymes produced by fungi are used industrially and in detergents. Fungi are also used as biological agents to control weeds and pests. Many species produce bioactive compounds called mycotoxins, such as alkaloids and polyketides, that are toxic to animals including humans. The fruiting structures of a few species are consumed recreationally or in traditional ceremonies as a source of psychotropic compounds. Fungi can break down manufactured materials and buildings, and become significant pathogens of humans and other animals. Losses of crops due to fungal diseases or food spoilage can have a large impact on human food supplies and local economies. Despite their importance on human affairs, little is known of the true biodiversity of Kingdom Fungi, which has been estimated at around 1.5 million species, with about 5% of these having been formally classified.

More about fungi...

Selected article

Amanita bisporigera fruit bodies
Amanita bisporigera is a deadly poisonous species of fungus in the Amanitaceae family. It is commonly known as the eastern North American destroying angel or the destroying angel, although it shares this latter name with three other lethal white Amanita species, A. ocreata, A. verna and A. virosa. The fruit bodies are found on the ground in mixed coniferous and deciduous forests of Eastern North America south to Mexico, but are rare in western North America; it has also been found in pine plantations in Colombia. The mushroom has a smooth white cap that can reach up to 10 cm (3.9 in) across, and a stem, up to 14 cm (5.5 in) by 1.8 cm (0.71 in) thick, that has a delicate white skirt-like ring near the top. The bulbous stem base is covered with a membranous sac-like volva. The white gills are free from attachment to the stalk and crowded closely together. As the species name suggests, A. bisporigera typically bears two spores on the basidia, although this characteristic is not as immutable as was once thought.

First described in 1906, A. bisporigera is classified in the section Phalloideae of the genus Amanita together with other amatoxin-containing species. Amatoxins are cyclic peptides which inhibit the enzyme RNA polymerase II and interfere with various cellular functions. The first symptoms of poisoning appear 6 to 24 hours after consumption, followed by a period of apparent improvement, then by symptoms of liver and kidney failure, and death after four days or more. Amanita bisporigera closely resembles a few other white amanitas, including the equally deadly A. virosa and A. verna. These species, difficult to distinguish from A. bisporigera based on visible field characteristics, do not have two-spored basidia, and do not stain yellow when a dilute solution of potassium hydroxide is applied. The DNA of A. bisporigera has been partially sequenced, and the genes responsible for the production of amatoxins have been determined.

Selected species

Psilocybe semilanceata 6514.jpg
Psilocybe semilanceata, commonly known as the liberty cap, is a psychedelic mushroom that contains the psychoactive compounds psilocybin and baeocystin. Liberty caps have a distinctive conical to bell-shaped cap, up to 2.5 centimetres (1.0 in)* in diameter, with a small nipple-like protrusion on the top. They are yellow to brown in color, covered with radial grooves when moist, and fade to a lighter color as they mature. Their stems tend to be slender and long, and the same color or slightly lighter than the cap. The gill attachment to the stem is adnexed (narrowly attached), and they are initially cream before tinting purple as the spores mature. The spores are dark purplish-brown in mass, ellipsoid, and measure 10.5–15 by 6.5–8.5 micrometers.

The mushroom grows on grassy meadows and similar habitats, particularly in wet, north-facing fields and other habitats well-fertilized by sheep and cattle feces. But unlike P. cubensis and P. coprophila, it does not grow directly on the dung. The species is found in fields where animals graze throughout the cool temperate and subarctic regions of the Northern Hemisphere, but it is known primarily from continental Europe, the UK and Ireland. However, it has also been reported occasionally from India, South America, and Australasia. It is the world's most common psychoactive mushroom, and one of the most potent. The mushroom has also been shown to inhibit an antibiotic-resistant form of the human pathogen Staphylococcus aureus, and it may suppress growth of the plant pathogen Phytophthora cinnamomi.

Things to do

If you want to help Wikipedia to improve its coverage of fungi, here are some things you can do...

WikiProjects

Selected picture

Did you know?

Categories

Topics

Related portals

Wikimedia

Fungi on Wiktionary     Fungi on Wikimedia Commons     Fungi on Wikispecies    
Definitions Images & Media Species directory
Wiktionary-logo-en-35px.png
Commons-logo.svg
Wikispecies-logo.svg