''Russula cyanoxantha'', synonymous with ''R. xyanoxantha'', commonly known as the charcoal burner, 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, Ba ...
mushroom
A mushroom or toadstool is the fleshy, spore-bearing fruiting body of a fungus, typically produced above ground, on soil, or on its food source. ''Toadstool'' generally denotes one poisonous to humans.
The standard for the name "mushroom" is ...
, distinguished from most other members of the genus ''
Russula
''Russula'' is a very large genus composed of around 750 worldwide species of ectomycorrhizal mushrooms. They are typically common, fairly large, and brightly colored – making them one of the most recognizable genera among mycologists and mushr ...
'' by the fact that its
gill
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 ...
s do not split, but are soft and flexible. It is one of the most common species of ''Russula'' in
Europe
Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a subcontinent of Eurasia and it is located entirel ...
.
It is an
edible mushroom. It was designated "Mushroom of the Year" in 1997 by the German Association of Mycology.
Description
The most salient characteristic is the weak gills, which feel greasy to the touch, are flexible and do not break. The cap is wide, convex at first and later flattened, and greenish to bright brown; they vary considerably in color.
The stipe is pure white, slightly convex underneath, from in height and in diameter.
The spores are pure white.
The stipe will give a green reaction when rubbed with iron salts (ferrous sulphate). Most other (but not all) ''Russula'' species give a salmon reaction. Coupled with the gill flexibility this is a good diagnostic clue to species level.
Distribution and habitat
''Russula cyanoxantha'' grows in slightly acidic, but nutrient-rich soil. Like all ''Russulas'', it is a
mycorrhizal fungus
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 ...
. It is found most commonly in
beech forests, and often in deciduous or mixed forests, appearing from May to November, with the highest concentration in July to September.
Use
The
edible mushroom is suitable for many kinds of preparation; the flesh is not as hard as that of many other edible Russulas. It has a mild,
nutty taste.
Similar species
The cap of the grey-green ''Russula grisea'' is more blue-grey but has violet or green hues with light cream gills; it also grows in mixed forests, particularly under beech, and more rarely in coniferous forests. ''Russula olivacea'' also may have a variegated cap, but produces yellow spores.
See also
*
List of ''Russula'' species
References
*E. Garnweidner. ''Mushrooms and Toadstools of Britain and Europe''. Collins. 1994.
External links
*
*
Russulales News page on ''Russula cyanoxantha''
{{Taxonbar, from=Q246696
cyanoxantha
Fungi of Europe
Edible fungi
Taxa named by Jacob Christian Schäffer
Fungi described in 1774