''Gyroporus castaneus'', or commonly the chestnut bolete, is a small, white-pored relation of the '' Boletus'' mushrooms. It has a brown cap, and is usually found with oak trees. It differs from the true boletes in that 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 a pale straw colour.

Taxonomy

The species was described initially by the French mycologist

Jean Baptiste François Pierre Bulliard Jean Baptiste François Pierre Bulliard (also Pierre Bulliard; 24 November 1752, in Aubepierre-sur-Aube Haute-Marne – 26 September 1793, in Paris) was a French physician and botanist. Bulliard studied in Langres, where he became interested ...

(1742–1792). Formerly a member of the family Paxillaceae, research now places this mushroom in Gyroporaceae. ''Gyroporus'' means 'having round pores', and ''castaneus'' is a reference to the chestnut colouration.

Description

The cap is from 3 to 10 cm in diameter, and pale to rusty brown in colour, which becomes darker with age. The

stem Stem or STEM may refer to: Plant structures * Plant stem, a plant's aboveground axis, made of vascular tissue, off which leaves and flowers hang * Stipe (botany), a stalk to support some other structure * Stipe (mycology), the stem of a mushro ...

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 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 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 ...

relationship with oaks ('' Quercus''). It prefers acid and sandy soils, and fruits from summer to autumn. In New Zealand, it is found in association with ''

Leptospermum ''Leptospermum'' is a genus of shrubs and small trees in the myrtle family Myrtaceae commonly known as tea trees, although this name is sometimes also used for some species of ''Melaleuca''. Most species are endemic to Australia, with the greate ...

''. In Asia, it has been recorded from Taiwan. ''Gyroporus castaneus'' has been included in the

Moscow Oblast Moscow Oblast ( rus, Моско́вская о́бласть, r=Moskovskaya oblast', p=mɐˈskofskəjə ˈobləsʲtʲ), or Podmoskovye ( rus, Подмоско́вье, p=pədmɐˈskovʲjə, literally "under Moscow"), is a federal subject of Rus ...

's and the Russian Federation's Red Book and several other countries' Red Lists, including those of Norway and Montenegro.

Edibility

''Gyroporus castaneus'' is edible, 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 strain of this mushroom in coastal Portugal.

References

External links