''Russula fragilis'', commonly known as the fragile russula, or fragile brittlegill, is a species of mushroom of the genus '' Russula'', whose members are commonly known as brittlegills. It is a small, fragile, long stemmed, and variably coloured brittlegill, found in mixed forests, and woods in Europe, Asia, and

North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...

Taxonomy

''Russula fragilis'' was first described as ''Agaricus fragilis'' by mycologist Christian Hendrik Persoon in 1801, and later placed in the genus '' Russula'' by

Elias Magnus Fries Elias Magnus Fries (15 August 1794 – 8 February 1878) was a Swedish mycologist and botanist. Career Fries was born at Femsjö (Hylte Municipality), Småland, the son of the pastor there. He attended school in Växjö. He acquired ...

in 1838.

Description

The cap is 2–5 cm (0.8–2 in) in diameter. It is very variable in colour, and can be dark purplish, with a dark, almost black centre, or may be various shades of olive-green, or violet-pink, or even pale yellow. The colour tends to fade quickly, and can become very pale. At first the cap shape is convex, but it later flattens. The cap skin peels to three quarters, and older specimens often have a furrowed margin. The fragile, white stipe is long for the size of the cap, and narrowly club-shaped. The gills are adnexed, and white giving a spore print of the same colour. They have distinctive nicks, or notches on their free edges, that can be seen under a hand lens, a very good diagnostic clue to species. The flesh is white and tastes very hot, with a fruity odour.

Similar species

Russula betularum ''Russula betularum'' is a small, very pale member of the ''Russula'' (brittlegills) genus of mushrooms. It is usually white to very pale pink, inedible, and grows with birch trees. It is commonly known as the birch brittlegill. Taxonomy The s ...

'' is frequently found with birch, and although usually paler can be mistaken for washed out specimens of ''R. fragilis''; '' Russula gracillima'' is similar in appearance, and grows in the same locations, although neither species have nicks (serrations) on the gill edges.

Distribution and habitat

''Russula fragilis'' appears in late summer and autumn, usually growing in small groups. It is widespread in the northern temperate zones of Europe, Asia, and North America. It is probably

mycorrhiza A mycorrhiza (from Greek μύκης ', "fungus", and ῥίζα ', "root"; pl. mycorrhizae, mycorrhiza or mycorrhizas) is a symbiotic association between a fungus and a plant. The term mycorrhiza refers to the role of the fungus in the plant ...

l with a variety of trees, including birch and oak. It often appears on or near rotted wood.

Toxicity

This mushroom is inedible due the toxins it contains and its very hot taste. Many hot-tasting ''Russula'' species cause problems of a gastrointestinal nature when consumed, resulting in diarrhoea, and vomiting.

References