Pleurotus tuber-regium, the king tuber mushroom, is an edible

Edible mushroom

Edible mushrooms are the fleshy and edible fruiting bodies of several species of fungi. Mushrooms belong to the macrofungi, because their fruiting structures are large enough to be seen with the naked eye. They can appear either below ground or above ground where they may be picked by hand...

 gilled

Agaricales

The fungal order Agaricales, also known as gilled mushrooms , or euagarics, contains some of the most familiar types of mushrooms. The order has 33 extant families, 413 genera, and over 13000 described species, along with five extinct genera known only from the fossil record...

 fungus native to the tropics, including Africa

Africa

Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...

, Asia

Asia

Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...

, and Australasia

Australasia

Australasia is a region of Oceania comprising Australia, New Zealand, the island of New Guinea, and neighbouring islands in the Pacific Ocean. The term was coined by Charles de Brosses in Histoire des navigations aux terres australes...

. It has been shown to be a distinct species incapable of cross-breeding and phylogenetically

Phylogenetics

In biology, phylogenetics is the study of evolutionary relatedness among groups of organisms , which is discovered through molecular sequencing data and morphological data matrices...

 removed from other species of Pleurotus

Pleurotus

Pleurotus is a genus of gilled mushrooms which includes one of the most widely eaten mushrooms, P. ostreatus. Species of Pleurotus may be called oyster, abalone, or tree mushrooms, and are some of the most commonly cultivated edible mushrooms in the world...

.

P. tuber-regium is a saprotroph found on dead wood

Wood-decay fungus

A wood-decay fungus is a variety of fungus that digests moist wood, causing it to rot. Some wood-decay fungi attack dead wood, such as brown rot, and some, such as Armillaria , are parasitic and colonize living trees. Fungi that not only grow on wood but actually cause it to decay, are called...

, including Daniellia

Daniellia

Daniellia is a genus of legume in the Fabaceae family, named after William Freeman Daniell.It contains the following species:* Daniellia klainei* Daniellia oblonga* Daniellia ogea* Daniellia oliveri...

trees in Africa. As the fungus consumes the wood, it produces a sclerotium

Sclerotium

A sclerotium is a compact mass of hardened fungal mycelium containing food reserves. One role of sclerotia is to survive environmental extremes. In some higher fungi such as ergot, sclerotia become detached and remain dormant until a favorable opportunity for growth. Other fungi that produce...

, or storage tuber, either within the decaying wood or in the underlying soil. These sclerotia are round, dark brown with white interiors, and up to 30 cm wide. The fruiting bodies

Basidiocarp

In fungi, a basidiocarp, basidiome or basidioma , is the sporocarp of a basidiomycete, the multicellular structure on which the spore-producing hymenium is borne. Basidiocarps are characteristic of the hymenomycetes; rusts and smuts do not produce such structures...

 then emerge from the sclerotium. Both the sclerotium and the fruiting bodies are edible.

In addition to being saprotrophic, P. tuber-regium is also nematophagous

Nematophagous fungus

Nematophagous fungi are carnivorous fungi specialized in trapping and digesting nematodes. Around 160 species are known. There exist both species that live inside the nematodes from the beginning and others that catch them mostly with glue traps or in rings, some of which constrict on contact. Some...

, catching nematode

Nematode

The nematodes or roundworms are the most diverse phylum of pseudocoelomates, and one of the most diverse of all animals. Nematode species are very difficult to distinguish; over 28,000 have been described, of which over 16,000 are parasitic. It has been estimated that the total number of nematode...

s by paralyzing them with a toxin.

P. tuber-regium has a history

Ethnomycology

Ethnomycology is the study of the historical uses and sociological impact of fungi , and can be considered a subfield of ethnobotany or ethnobiology...

 of economic importance in Africa as food and as a medicinal mushroom

Medicinal mushrooms

Medicinal mushrooms are mushrooms, or mushroom extracts, that are used or studied as possible treatments for diseases. Lentinula edodes , Grifola frondosa , Ganoderma lucidum , and Cordyceps, have a history of medicinal use spanning millennia in parts of Asia...

. Industrial cultivation is not yet common, but studies have shown P. tuber-regium can be grown on organic wastes such as corn

Maize

Maize known in many English-speaking countries as corn or mielie/mealie, is a grain domesticated by indigenous peoples in Mesoamerica in prehistoric times. The leafy stalk produces ears which contain seeds called kernels. Though technically a grain, maize kernels are used in cooking as a vegetable...

 and sawdust

Sawdust

Sawdust is a by-product of cutting lumber with a saw, composed of fine particles of wood. It can present a hazard in manufacturing industries, especially in terms of its flammability....

. Mycelial growth occurs between 15°C and 40°C, with an optimum growth rate at 35°C.

External links

• Biological Species in Pleurotus: ISG X. Pleurotus tuber-regium at University of Tennessee-Knoxville Mycology Lab