''Russula claroflava'', commonly known as the yellow russula, yellow swamp russula or yellow swamp brittlegill, is a

basidiomycete Basidiomycota () is one of two large divisions that, together with the Ascomycota, constitute the subkingdom Dikarya (often referred to as the "higher fungi") within the kingdom Fungi. Members are known as basidiomycetes. More specifically, Basid ...

mushroom of the genus ''

Russula ''Russula'' is a very large genus composed of around 750 worldwide species of fungi. The genus was described by Christian Hendrik Persoon in 1796. The mushrooms are fairly large, and brightly colored – making them one of the most recognizable ...

''. It has a yellow

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. The origin of the word "cap" comes from the Old French word "chapeau" which means "head co ...

, white

gills A gill () is a respiratory organ that many aquatic organisms use to extract dissolved oxygen from water and to excrete carbon dioxide. The gills of some species, such as hermit crabs, have adapted to allow respiration on land provided they are ...

and stipe and bruises grey. The species is found in wet places under

birch A birch is a thin-leaved deciduous hardwood tree of the genus ''Betula'' (), in the family Betulaceae, which also includes alders, hazels, and hornbeams. It is closely related to the beech- oak family Fagaceae. The genus ''Betula'' contains 3 ...

and

aspen Aspen is a common name for certain tree species in the Populus sect. Populus, of the ''Populus'' (poplar) genus. Species These species are called aspens: * ''Populus adenopoda'' – Chinese aspen (China, south of ''P. tremula'') * ''Populus da ...

woodlands across Europe and North America. It is mild-tasting and regarded as a good

edible mushroom Edible mushrooms are the fleshy fruit bodies of numerous species of macrofungi (fungi that bear fruiting structures large enough to be seen with the naked eye). Edibility may be defined by criteria including the absence of poisonous effect ...

Taxonomy

It was described in 1888 by

William Bywater Grove William Bywater Grove (24 October 1848 – 6 January 1938), was an English biologist, in particular a botanist and microbiologist. He is remembered in particular as a mycologist. He died in 1938 on the sixth of January when he was 89.New York Bot ...

, based on a specimen from Sutton Park in the English Midlands. Its

specific epithet In Taxonomy (biology), taxonomy, binomial nomenclature ("two-term naming system"), also called binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin gramm ...

is derived from the

Latin Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...

''clarus'' 'bright' or 'clear', and ''flava'' 'light yellow'.

Description

This medium-sized member of the genus ''

'' has a

that is an egg-yolk yellow. Measuring in diameter, it is slightly sticky when moist, and leaves and other debris often stick to it. There is usually a slight depression in the centre of mature specimens, with the margin becoming furrowed. The

is half peeling. The

stem Stem or STEM most commonly refers to: * Plant stem, a structural axis of a vascular plant * Stem group * Science, technology, engineering, and mathematics Stem or STEM can also refer to: Language and writing * Word stem, part of a word respon ...

is 3–8 cm long, white, fairly firm, straight and 1–2 cm thick. Its

are pale ochre, and are adnexed to almost free. All parts turn dark grey on aging or bruising. The smell is fruity and 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 warm orange ("tussock") color spore print. ...

is pale ochre, and the oval warty spores average 9.5 x 8

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

Similar species

The edible but acrid ''

Russula ochroleuca ''Russula ochroleuca'' is a member of the genus ''Russula''. A group that have become known as brittlegills. It has been commonly known as the common yellow russula for some years, and latterly the ochre brittlegill. It is widespread, and commo ...

'' resembles this species, but has a duller yellow cap. '' R. lutea'' is also similar.

Distribution and habitat

''Russula claroflava'' appears in summer and autumn, usually with birch (''

Betula A birch is a thin-leaved deciduous hardwood tree of the genus ''Betula'' (), in the family Betulaceae, which also includes alders, hazels, and hornbeams. It is closely related to the beech- oak family Fagaceae. The genus ''Betula'' contains 3 ...

''), or aspen (''

Populus ''Populus'' is a genus of 25–30 species of deciduous flowering plants in the family Salicaceae, native to most of the Northern Hemisphere. English names variously applied to different species include poplar (), aspen, and cottonwood. The we ...

''), on heaths and moors, preferring damp places near ponds or lakes, often occurring in

sphagnum ''Sphagnum'' is a genus of approximately 380 accepted species of mosses, commonly known as sphagnum moss, also bog moss and quacker moss (although that term is also sometimes used for peat). Accumulations of ''Sphagnum'' can store water, since ...

. It is occasionally found in drier places. It occurs in Britain, across northern Europe, and throughout North America.

Edibility

This mushroom 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 good, with a mild taste, both in Europe and North America.

References

Cited literature

*Marcel Bon, ''The Mushrooms and Toadstools of Britain and North Western Europe''. *Courtecuisse and Duhem, ''Mushrooms and Toadstools of Britain and Europe''. {{Taxonbar, from=Q1462183 claroflava Edible fungi Fungi described in 1888 Fungi of Europe Fungi of North America Fungus species