''Gymnopilus junonius'' is a species of

mushroom A mushroom or toadstool is the fleshy, spore-bearing fruiting body of a fungus, typically produced above ground, on soil, or on its food source. ''Toadstool'' generally denotes one poisonous to humans. The standard for the name "mushroom" is ...

-forming

fungus A fungus ( : fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, separately from t ...

in the family

Hymenogastraceae The Hymenogastraceae is a family of fungi in the order Agaricales with both agaric and false-truffle shaped fruitbodies. Formerly, prior to molecular analyses, the family was restricted to the false-truffle genera. The mushroom genus ''Psilocybe ...

. Commonly known as the spectacular rustgill, this large orange mushroom is typically found growing on tree stumps, logs, or tree bases. Some subspecies of this mushroom contain the

neurotoxic Neurotoxicity is a form of toxicity in which a biological, chemical, or physical agent produces an adverse effect on the structure or function of the central and/or peripheral nervous system. It occurs when exposure to a substance – specificall ...

oligoisoprenoid gymnopilin.

Description

The

cap A cap is a flat headgear, usually with a visor. Caps have crowns that fit very close to the head. They made their first appearance as early as 3200 BC. Caps typically have a visor, or no brim at all. They are popular in casual and informal se ...

ranges from across, is convex to flat, and is bright yellow-orange in younger specimens and orange-brown or reddish brown in older ones, with a dry scaly surface. The

flesh Flesh is any aggregation of soft tissues of an organism. Various multicellular organisms have soft tissues that may be called "flesh". In mammals, including humans, ''flesh'' encompasses muscles, fats and other loose connective tissues, but ...

is yellow, the odor mild and taste bitter. The stem is long, 1–5 cm thick, and often narrows near the base. The frail

ring Ring may refer to: * Ring (jewellery), a round band, usually made of metal, worn as ornamental jewelry * To make a sound with a bell, and the sound made by a bell :(hence) to initiate a telephone connection Arts, entertainment and media Film and ...

is dusted with rusty orange

spores In biology, a spore is a unit of sexual or asexual reproduction that may be adapted for dispersal and for survival, often for extended periods of time, in unfavourable conditions. Spores form part of the life cycles of many plants, algae, ...

, and the gill attachment to the stem is

adnate Adnate may refer to: * Adnation, in botany, the fusion of two or more whorls of a flower * Adnate, in mycology, a classification of lamellae (gills) * Conjoined twins Conjoined twins – sometimes popularly referred to as Siamese twins – are ...

to sub-decurrent. It stains red with KOH and turns green when cooked. The

spore print 300px, Making a spore print of the mushroom ''Volvariella volvacea'' shown in composite: (photo lower half) mushroom cap laid on white and dark paper; (photo upper half) cap removed after 24 hours showing pinkish-tan spore print. A 3.5-centimeter ...

is rusty orange. Unlike psychoactive relatives in the ''

Psilocybe ''Psilocybe'' ( ) is a genus of gilled mushrooms, growing worldwide, in the family Hymenogastraceae. Most or nearly all species contain the psychedelic compounds psilocybin and psilocin. Taxonomy Taxonomic history A 2002 study of the mol ...

'' genus, ''G. junonius'' lacks psilocybin and does not stain blue, but smaller specimens occasionally exhibit bruising. This mushroom usually grows in clusters from several to several dozen individuals, but sometimes grows solitary. It is inedible due to its bitter taste. Gymnopilus junonius

Similar species

This mushroom is often mistaken for '' Gymnopilus ventricosus'', which also contains no

psilocybin Psilocybin ( , ) is a naturally occurring psychedelic prodrug compound produced by more than 200 species of fungi. The most potent are members of the genus ''Psilocybe'', such as '' P. azurescens'', '' P. semilanceata'', and '' P.&nbs ...

and ''G. luteus'' and ''G. subspectabilis'', which do. It also resembles ''

Armillaria mellea ''Armillaria mellea'', commonly known as honey fungus, is a basidiomycete fungus in the genus ''Armillaria''. It is a plant pathogen and part of a cryptic species complex of closely related and morphologically similar species. It causes Armill ...

'' and ''

Omphalotus olivascens ''Omphalotus olivascens'', commonly known as the western jack-o'-lantern mushroom, is an orange to brown-colored gilled mushroom native to California and Mexico. Taxonomy The fungus was described as new to science in 1976 by American mycologis ...

''.

Distribution and habitat

''Gymnopilus junonius'' is found in Europe,

Australasia Australasia is a region that comprises Australia, New Zealand and some neighbouring islands in the Pacific Ocean. The term is used in a number of different contexts, including geopolitically, physiogeographically, philologically, and ecologi ...

and South America. It grows in dense clusters on stumps and logs of hardwoods and conifers. This mushroom is most common in moist, lowland wooded areas near rivers. This species does not occur in North America; however some similar looking species do. These include '' Gymnopilus ventricosus'' on the west coast and ''G. luteus'' and ''G. subspectabilis'' in the midwest and east.

Biochemistry

This mushroom contains bis-noryangonin and

hispidin Hispidin is a natural substance. It can also be synthesized. Hispidin 4-''O''-β-D-glucopyranoside can be found in ''Pteris ensiformis'' whereas hispidin derivatives, such as phellibaumins, can be found in the edible mushroom '' Inonotus xerantic ...

, which are structurally related to alpha-pyrones found in kava. Neurotoxins known as oligoisoprenoids have also been found in this species.

References

*C.J. Alexopolous, Charles W. Mims, M. Blackwell et al., ''Introductory Mycology, 4th ed.'' (John Wiley and Sons, Hoboken NJ, 2004)

External links