''Gyroporus castaneus'', or commonly the chestnut bolete, is a small, white-pored relation of the ''

Boletus ''Boletus'' is a genus of mushroom-producing fungi, comprising over 100 species. The genus ''Boletus'' was originally broadly defined and described by Carl Linnaeus in 1753, essentially containing all fungi with hymenial pores instead of ...

'' mushrooms. It has a brown

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 ...

, and is usually found with

oak An oak is a tree or shrub in the genus ''Quercus'' (; Latin "oak tree") of the beech family, Fagaceae. There are approximately 500 extant species of oaks. The common name "oak" also appears in the names of species in related genera, notably ''L ...

trees. It differs from the true boletes in that the spores are a pale straw colour.

Taxonomy

The species was described initially by the French mycologist Jean Baptiste François Pierre Bulliard (1742–1792). Formerly a member of the

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

Paxillaceae The Paxillaceae are a family of mushroom-forming fungi bearing close affinity to the boletes. Collectively, the family contains nine genera and 78 species. The type genus is ''Paxillus'', containing fungi with decurrent gills, and ''Gyrodon'', ...

, research now places this mushroom in

Gyroporaceae The Gyroporaceae are a family of fungi in the order Boletales. The family is monogeneric, containing the single genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well ...

. ''Gyroporus'' means 'having round pores', and ''castaneus'' is a reference to the chestnut colouration.

Description

The

is from 3 to 10 cm in diameter, and pale to rusty brown in colour, which becomes darker with age. The stem is a similar colour, although it may be lighter at the apex. If the stem is cut vertically, it is usual to find several cavities of differing sizes inside. Both the cap and the stem have a tendency to crack or split in dry periods, or with age. The pores are small and white; they become dirtier with age, and are not attached to the stem. They darken slightly when pressed. The tubes are also whitish, and the spore print is pale yellow to straw. 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 firm, and does not change colour on cutting. The photograph on the right shows the chunkier form; a slender form also occurs. Gyro

Distribution and habitat

The mushroom is found occasionally in Britain and throughout continental Europe, as well as eastern North America, but it is rare in western North America. It grows in small groups, or singly, in an ectomycorrhizal relationship with oaks (''

Quercus An oak is a tree or shrub in the genus ''Quercus'' (; Latin "oak tree") of the beech family, Fagaceae. There are approximately 500 extant species of oaks. The common name "oak" also appears in the names of species in related genera, notably ...

''). It prefers acid and sandy soils, and fruits from summer to autumn. In New Zealand, it is found in association with '' Leptospermum''. In Asia, it has been recorded from Taiwan. ''Gyroporus castaneus'' has been included in the Moscow Oblast's and the

Russian Federation Russia (, , ), or the Russian Federation, is a transcontinental country spanning Eastern Europe and Northern Asia. It is the largest country in the world, with its internationally recognised territory covering , and encompassing one-eig ...

's Red Book and several other countries' Red Lists, including those of

Norway Norway, officially the Kingdom of Norway, is a Nordic country in Northern Europe, the mainland territory of which comprises the western and northernmost portion of the Scandinavian Peninsula. The remote Arctic island of Jan Mayen and the ...

and

Montenegro ) , image_map = Europe-Montenegro.svg , map_caption = , image_map2 = , capital = Podgorica , coordinates = , largest_city = capital , official_languages = M ...

Edibility

''Gyroporus castaneus'' is

edible An edible item is any item that is safe for humans to eat. "Edible" is differentiated from "eatable" because it does not indicate how an item tastes, only whether it is fit to be eaten. Nonpoisonous items found in nature – such as some mushroo ...

, and highly regarded by most authors; it is said to taste pleasantly nutty when young. However, Marcel Bon, in his 1987 book ''The Mushrooms and Toadstools of Britain and North Western Europe'', records it as suspect, so it may be worth applying caution, by eating a very small amount initially. There is also reportedly a

poisonous Poison is a chemical substance that has a detrimental effect to life. The term is used in a wide range of scientific fields and industries, where it is often specifically defined. It may also be applied colloquially or figuratively, with a broa ...

strain of this mushroom in coastal Portugal.

References

External links