''Gymnogaster'' is a genus of fungi in the family Boletaceae. It is a monotypic genus, containing the single secotioid species ''Gymnogaster boletoides'', found in Australia. The fungus produces bright yellow

fruit bodies The sporocarp (also known as fruiting body, fruit body or fruitbody) of fungi is a multicellular structure on which spore-producing structures, such as basidia or asci, are borne. The fruitbody is part of the sexual phase of a fungal life cyc ...

with a light brown internal gleba, and the fruit bodies turn blue then dark brown after bruising or handling.

Taxonomy and classification

The genus was

circumscribed In geometry, the circumscribed circle or circumcircle of a polygon is a circle that passes through all the vertices of the polygon. The center of this circle is called the circumcenter and its radius is called the circumradius. Not every polyg ...

by Joan Cribb in 1956, based on specimens she found growing in the woods of

Mount Glorious, Queensland Mount Glorious is a rural locality in the Moreton Bay Region, Queensland, Australia. In the , Mount Glorious had a population of 296 people. Geography Mount Glorious is a mountain which is part of the D'Aguilar Range and is a suburb in Moreton B ...

in February the previous year. The genus differs from the similar ''

Secotium ''Secotium'' is a genus of fungi in the family Agaricaceae. The members of this genus are closely related to ordinary ''Agaricus'' mushrooms, but do not open out in the usual way; this has given rise to the term "secotioid" for such mushrooms in ...

'' in that it lacks a peridium. Cribb initially placed the genus within the Secotiaceae family, but this has since been made

synonymous A synonym is a word, morpheme, or phrase that means exactly or nearly the same as another word, morpheme, or phrase in a given language. For example, in the English language, the words ''begin'', ''start'', ''commence'', and ''initiate'' are all ...

with the Agaricaceae. In his second (1962) edition of his influential ''Agaricales in Modern Taxonomy'',

Rolf Singer Rolf Singer (June 23, 1906 – January 18, 1994) was a Germany, German-born mycologist and one of the most important Taxonomy (biology), taxonomists of gilled mushrooms (agarics) in the 20th century. After receiving his Ph.D. at the University ...

placed ''Gymnogaster'' in the Gastroboletaceae, (a family that has since been folded into the Boletaceae),Kirk ''et al.'' (2008), p. 274. in which he also included the genera '' Austrogaster'', ''

Truncocolumella ''Truncocolumella'' is a genus of fungi in the family Suillaceae, of the order Boletales. It was circumscribed by American mycologist Sanford Myron Zeller Sanford Myron Zeller (19 October 1885 – 4 November 1948) was an American mycologist. ...

'', ''

Gautieria ''Gautieria'' is a genus of hypogeal fungi in the family Gomphaceae. They form mycorrhizae with various tree species, mostly from the family Pinaceae. Species are present over much of the world's temperate and boreal forest habitats. It is well d ...

'', ''

Chamonixia ''Chamonixia'' is a genus of truffle-like fungi in the family Boletaceae. The genus is widely distributed, especially in temperate regions, and contains eight species. ''Chamonixia'' was circumscribed by French mycologist Léon Louis Rolland ...

'', '' Brauniellula'', and ''

Gastroboletus ''Gastroboletus'' is a genus of fungi in the family Boletaceae. Species in the genus have misshapen caps, poorly developed or absent stipes, and are often buried or partially buried. ''Gastroboletus'' has tubes arranged irregularly, rather than ...

''.

Description

The

fruit body In botany, a fruit is the seed-bearing structure in flowering plants that is formed from the Ovary (plants), ovary after flowering plant, flowering. Fruits are the means by which flowering plants (also known as angiosperms) disseminate their ...

is shaped roughly like a flattened sphere, about wide and high (excluding the stipe). The base of the fruit body is depressed and rounded, yellow; at the apex, the fixed part is russet red. The stipe is yellow on the outside but white within, projecting into the fruit body; it is long, thick, and solid. The columella (a central sterile portion) is white and wide. The gleba is cellular, pale brown, and composed of labyrinthoid cells that are up to 1 mm in diameter. The flesh is 50–70

μm The micrometre ( international spelling as used by the International Bureau of Weights and Measures; SI symbol: μm) or micrometer (American spelling), also commonly known as a micron, is a unit of length in the International System of Unit ...

thick, with a wide expanse of woven

hypha A hypha (; ) is a long, branching, filamentous structure of a fungus, oomycete, or actinobacterium. In most fungi, hyphae are the main mode of vegetative growth, and are collectively called a mycelium. Structure A hypha consists of one or ...

e. The

spore 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, f ...

s are elliptical or ovate, brown, smooth, and measure 9.5–13 by 5.6–7.0

. The basidia are four-spored. Fruit bodies of ''G. boletoides'' will turn bright blue immediately upon being handled or bruised, and slowly change color to dark brown. This is similar to the color reaction that occurs in several bolete mushrooms.

Habitat and distribution

''Gymnogaster boletoides'' is suspected to be an

ectomycorrhizal An ectomycorrhiza (from Greek ἐκτός ', "outside", μύκης ', "fungus", and ῥίζα ', "root"; pl. ectomycorrhizas or ectomycorrhizae, abbreviated EcM) is a form of symbiotic relationship that occurs between a fungal symbiont, or mycobi ...

species. The fungus grows in wooded areas, and has been collected in

, including Lamington National Park.

References

External links

* {{taxonbar , from1=Q1610174, from2=Q10511459 Agaricaceae Monotypic Agaricales genera Fungi of Australia Taxa described in 1956

Taxonomy and classification

Description

Habitat and distribution

See also

References

External links