Russula nobilis

Russula nobilis

The Beechwood Sickener (Russula nobilis Velen., 1920). It is a mushroom belonging to the Russulaceae family.

Systematics –
Domain Eukaryota,
Kingdom Fungi,
Phylum Basidiomycota,
Class Basidiomycetes,
Order Russulales,
Family Russulaceae,
Genus Russula,
Species R. nobilis.
The terms are synonymous with:
– Russula emetica f. fageticola (Melzer) Konrad & Maubl.;
– Russula emetica var. mairei (Singer) Killerm.;
– Russula emetica var. nobilis (Velen.) Melzer & Zvara;
– Russula fageticola (Romagn.) Bon;
– Russula fageticola Melzer;
– Russula fageticola Melzer ex S.Lundell;
– Russula fageticola var. strenua Carteret & Moënne-Locc.;
– Russula fagetorum Bon;
– Russula mairei Singer;
– Russula mairei var. fageticola Melzer;
– Russula mairei var. fageticola Romagn.;
– Russula nobilis var. semilucida R.Socha.

Etymology –
The term Russula is the diminutive of russus, red: slightly reddish, a term attributed to the presence in this family of mushrooms with a predominantly red color.
The epithet mairei, by which this species has long been known, pays homage to the French mycologist René Charles Joseph Ernest Maire (1878-1949), one of the greatest European mushroom scholars of the last century. The attribution of the name is due to Rolf Singer, who described the species in 1929, dedicating it to Maire.
Subsequent studies, however, have clarified that Russula mairei is not a distinct species, but rather coincides with Russula nobilis, described as early as 1920 by Velenovský. Since the principle of priority applies in botanical and mycological nomenclature, the correct name accepted today is Russula nobilis, while Russula mairei is considered a synonym.
The epithet nobilis, applied to several mushroom species (such as Russula nobilis or Boletus nobilis), derives from the classical Latin “nobilis” (illustrious, noble, excellent). It indicates prized qualities, either for their elegant appearance or for their reputation as an excellent edible mushroom compared to others.

Geographic Distribution and Habitat –
Russula nobilis is an ectomycorrhizal fungus that lives in symbiosis almost exclusively with beech (Fagus), particularly the European beech (Fagus sylvatica). Its distribution therefore closely follows that of its host tree.
It is a very common species and well represented throughout much of Western and Central Europe, where it regularly appears in mature beech forests. Outside Europe, it is also reported in North Africa, especially Morocco, Asia, and North America, always in areas where Fagus species grow. It prefers broadleaf forests, especially pure or mixed beech forests, on acidic to moderately acidic soils, often sandy or loamy, but can also occur on calcareous substrates. It bears fruit from midsummer to autumn, generally from July to October, and is one of the most common Russulas in acidic beech forests at medium altitude.

Recognition –
The species belongs to the Russula section, a group that includes rather small mushrooms, characterized by fragile fruiting bodies, a more or less intense red cap, a white stipe without a veil, and decidedly peppery flesh. The spore print is clear, ranging from white to pale yellow, and microscopically, dermatocystidia, often multiseptate, are well represented.
The cap of Russula nobilis typically measures between 3 and 9 centimeters in diameter, most often around 4-6 centimeters. When young, it is hemispherical or convex, then tends to flatten and sometimes becomes slightly depressed in the center. The cuticle is shiny and slightly sticky in humid weather, while it appears opaque and velvety when dry; it can be separated for about a third or up to half of the radius. The color is one of the most striking characteristics: a deep vermilion or carmine red, which often fades in the center to a cream or cream-ivory hue with age. The margin is initially smooth, but becomes grooved only in advanced stages.
The gills are white, dense, and very fragile; sometimes they display delicate glaucous or yellowish highlights. They are attached or slightly adnate to the stipe, often forked and interspersed with lamellule. With age or following chemical reactions, they may take on a light yellowish hue.
The stipe is cylindrical, rather short, and squat, 2 to 8 centimeters long and about 1 to 1.5 centimeters thick. It is white, with a slightly wrinkled surface and a robust consistency; as it ages, it tends to take on brown-ochre hues. Internally, it is stuffed and covered with a rather rigid bark.
The flesh is firm and compact, white in color, sometimes slightly yellowing in the exposed areas. The odor is pleasant and reminiscent of coconut or fruity notes; once dried, the mushroom may even develop a faint honeyed aroma. The flavor, however, is extremely peppery and pungent, so much so that it is immediately unpleasant. The fruit bodies are often attacked by snails.
Microscopically, the spores are obovoid-elliptical, averaging 6.6–8.5 µm long and 5.6–6.7 µm wide, with low warts connected by thin ridges that form a fairly dense network. The spore print is white. The basidia are tetrasterigmatic, and the cystidia, elongated and slightly ventricose, stain blue in sulfovanillin. The cap cuticle is composed of very fine hairs and club-shaped pileocystidia, with clearly visible multiseptate dermatocystidia.
Chemical reactions are a useful aid in identification: guaiac gives a rapid positive reaction, ammonia is negative, while aniline applied to the gills produces a rusty-orange color. The cuticle reacts to KOH, turning yellowish-brown, while the flesh discolors almost immediately. Other reagents, such as nitric acid, sulfovanillin, or ferrous sulfate, produce characteristic color variations.

Cultivation –
Like all ectomycorrhizal Russulas, Russula nobilis cannot be cultivated artificially. The species depends strictly on symbiosis with beech roots and the complex biological network of the forest soil, conditions that cannot be reliably reproduced in controlled cultivation.

Uses and Traditions –
Russula nobilis, as mentioned, was long known as Russula mairei in honor of the French mycologist René Charles Joseph Ernest Maire (1878-1949), one of the leading European mushroom researchers of the last century.
Russula nobilis is known by several local names. In Italy, it is sometimes referred to as the “beech mushroom” or “mushroom that sickens the beech,” underscoring its close ecological connection to this tree.
In Anglo-Saxon countries, it is often referred to as the “Beechwood Sickener.”
There are no known culinary, medicinal, or ritual uses associated with this species. In popular culture, it is primarily known as one of the inedible red Russulas of beech forests, easily recognizable but to be avoided.
It should be noted, in fact, that the species is not only inedible (ineditable) and likely toxic if consumed in large quantities, but can also cause symptoms such as nausea, vomiting, diarrhea, and gastrointestinal pain. Toxicity is not considered fatal in most cases, but should still be avoided.
Chemical compounds such as sesquiterpenes are responsible for this effect (although not yet precisely identified for this species).

Preparation Methods –
There are no recommended preparation methods. Russula nobilis is inedible and potentially toxic if ingested in large quantities. Consumption can cause gastrointestinal disorders such as nausea, vomiting, diarrhea, and abdominal cramps. The substances responsible have not been identified with certainty, but it is believed that chemical compounds belonging to the sesquiterpenes, also known in other Russulaceae, are responsible for its toxicity. The strongly acrid flavor, however, is an effective natural deterrent to consumption.

Guido Bissanti

Sources
– Wikipedia, the free encyclopedia.
– GBIF, the Global Biodiversity Information Facility.
– Cetto B., 2008. I funghi dal vero, Saturnia, Trento.
– Pignatti S., 1982. Flora d’Italia, Edagricole, Bologna.
– Conti F., Abbate G., Alessandrini A., Blasi C. (eds.), 2005. An annotated checklist of the Italian vascular flora, Palombi Editore.

Photo source:
– https://svampe.databasen.org/uploads/2021-10192527_S1H8fEDR_.JPG

Warning: The pharmaceutical applications and dietary uses are provided for informational purposes only and do not in any way constitute medical prescriptions. We therefore decline any responsibility for their use for curative, aesthetic, or nutritional purposes.