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

Mushroom

A mushroom is the fleshy, spore-bearing fruiting body of a fungus, typically produced above ground on soil or on its food source. The standard for the name "mushroom" is the cultivated white button mushroom, Agaricus bisporus; hence the word "mushroom" is most often applied to those fungi that...

 of the genus Russula

Russula

Around 750 worldwide species of mycorrhizal mushrooms compose the genus Russula. They are typically common, fairly large, and brightly colored - making them one of the most recognizable genera among mycologists and mushroom collectors...

. It is found in wet places under birch

Birch

Birch is a tree or shrub of the genus Betula , in the family Betulaceae, closely related to the beech/oak family, Fagaceae. The Betula genus contains 30–60 known taxa...

 and aspen

Aspen

Populus section Populus, of the Populus genus, includes the aspen trees and the white poplar Populus alba. The five typical aspens are all native to cold regions with cool summers, in the north of the Northern Hemisphere, extending south at high altitudes in the mountains. The White Poplar, by...

 woodlands across Europe and North America. It has a yellow cap

Pileus (mycology)

The pileus is the technical name for the cap, or cap-like part, of a basidiocarp or ascocarp that supports a spore-bearing surface, the hymenium. The hymenium may consist of lamellae, tubes, or teeth, on the underside of the pileus...

, white gills and stipe

Stipe (mycology)

thumb|150px|right|Diagram of a [[basidiomycete]] stipe with an [[annulus |annulus]] and [[volva |volva]]In mycology a stipe refers to the stem or stalk-like feature supporting the cap of a mushroom. Like all tissues of the mushroom other than the hymenium, the stipe is composed of sterile hyphal...

 and bruises grey. It is mild-tasting and regarded as good to eat.

Taxonomy

It was described in 1888 by William Bywater Grove. Its specific epithet is derived from the Latin

Latin

Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...

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

Description

This medium sized member of the genus Russula

Russula

Around 750 worldwide species of mycorrhizal mushrooms compose the genus Russula. They are typically common, fairly large, and brightly colored - making them one of the most recognizable genera among mycologists and mushroom collectors...

has a cap

Pileus (mycology)

The pileus is the technical name for the cap, or cap-like part, of a basidiocarp or ascocarp that supports a spore-bearing surface, the hymenium. The hymenium may consist of lamellae, tubes, or teeth, on the underside of the pileus...

 that is an egg-yolk yellow. Measuring 4–10 cm (1.5 4 in) in diameter, it is slightly sticky, 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 cap

Pileus (mycology)

The pileus is the technical name for the cap, or cap-like part, of a basidiocarp or ascocarp that supports a spore-bearing surface, the hymenium. The hymenium may consist of lamellae, tubes, or teeth, on the underside of the pileus...

 is half peeling. The 4–10 cm (1.5–4 in) high stem

Stipe (mycology)

thumb|150px|right|Diagram of a [[basidiomycete]] stipe with an [[annulus |annulus]] and [[volva |volva]]In mycology a stipe refers to the stem or stalk-like feature supporting the cap of a mushroom. Like all tissues of the mushroom other than the hymenium, the stipe is composed of sterile hyphal...

 is white, fairly firm, straight and 1–2 cm thick. Its gills 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

Spore print

thumb|300px|right|Making a spore print of the mushroom Volvariella volvacea shown in composite: mushroom cap laid on white and dark paper; cap removed after 24 hours showing pinkish-tan spore print...

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

Micrometre

A micrometer , is by definition 1×10-6 of a meter .In plain English, it means one-millionth of a meter . Its unit symbol in the International System of Units is μm...

. The edible but acrid Russula ochroleuca

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...

resembles this species, but has a duller yellow cap.

Distribution and habitat

Russula claroflava appears in summer and autumn, usually with birch (Betula), or aspen (Populus), on heaths and moors, preferring damp places near ponds or lakes, often occurring in sphagnum

Sphagnum

Sphagnum is a genus of between 151 and 350 species of mosses commonly called peat moss, due to its prevalence in peat bogs and mires. A distinction is made between sphagnum moss, the live moss growing on top of a peat bog on one hand, and sphagnum peat moss or sphagnum peat on the other, the...

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

Edibility

This mushroom is edible

Edible mushroom

Edible mushrooms are the fleshy and edible fruiting bodies of several species of fungi. Mushrooms belong to the macrofungi, because their fruiting structures are large enough to be seen with the naked eye. They can appear either below ground or above ground where they may be picked by hand...

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