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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. Their distinguishing characteristics include a white to dark yellow spore print
Spore print

The spore print of a mushroom is an important diagnostic character in most handbooks for identifying mushrooms. It shows the color of the mushroom spores if viewed en masse....
, brittle free white gills
Gill (mushroom)

A gill, or lamella, is a papery hymenophore rib under the cap of a mushroom, most often but not always an agaric. As fungi are studied in more detail, several other types of fungi exhibit gills while not members of the Agaricales....
, and an absence of partial veil
Partial veil

Partial veil is a mycology term which describes a structure of some mushrooms which protects the developing gill or other spore-producing surface....
 or volva
Universal veil

The universal veil is a Mycology term to describe a structure that envelops all or most of some gilled mushrooms. The young, developing Agaricus bisporus, which may resemble a puffball at this point, is protected by this egg-like structure....
 tissue on the stem. Members of the related Lactarius
Lactarius

Fungi of the genus Lactarius, sometimes called milk-caps, are characterized by the fact that they exude a milky fluid if cut or damaged....
 genus have similar characteristics but emit a milky latex when their gills are broken.






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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. Their distinguishing characteristics include a white to dark yellow spore print
Spore print

The spore print of a mushroom is an important diagnostic character in most handbooks for identifying mushrooms. It shows the color of the mushroom spores if viewed en masse....
, brittle free white gills
Gill (mushroom)

A gill, or lamella, is a papery hymenophore rib under the cap of a mushroom, most often but not always an agaric. As fungi are studied in more detail, several other types of fungi exhibit gills while not members of the Agaricales....
, and an absence of partial veil
Partial veil

Partial veil is a mycology term which describes a structure of some mushrooms which protects the developing gill or other spore-producing surface....
 or volva
Universal veil

The universal veil is a Mycology term to describe a structure that envelops all or most of some gilled mushrooms. The young, developing Agaricus bisporus, which may resemble a puffball at this point, is protected by this egg-like structure....
 tissue on the stem. Members of the related Lactarius
Lactarius

Fungi of the genus Lactarius, sometimes called milk-caps, are characterized by the fact that they exude a milky fluid if cut or damaged....
 genus have similar characteristics but emit a milky latex when their gills are broken. The genus was described by Christian Hendrik Persoon
Christian Hendrik Persoon

Christiaan Hendrik Persoon was a mycologist who made additions to Carolus Linnaeus' mushroom taxonomy....
 in 1796.

Identification

Like the genus Lactarius, Russulas have a distinctive flesh consistency
Russulaceae

Russulaceae is a family of fungi in the order Russulales. Its species have typically friable, chalk-like stalks, that break with a distinct crack, like a carrot but with porous flesh ....
, which is also reflected in the appearance of the gills and stipe, and normally makes them immediately recognizable. They have no trace of a veil (no ring, or veil remnants on the cap). The gills are brittle except in a few cases, and cannot be bent parallel with the cap without breaking. The spore powder varies from white to cream, or even orange.

While it is relatively easy to identify a sample mushroom as belonging to this genus, it is a significant challenge to distinguish member species of Russula. This task often requires microscopic characteristics, and subtle subjective distinctions, such as the difference between a mild to bitter and a mild to acrid flavor. Moreover the exact phylogenetic relationships of these mushrooms have yet to be resolved in the professional mycological community, and may ultimately depend on DNA sequencing
DNA sequencing

The term DNA sequencing refers to methods for determining the order of the nucleotide bases, adenine, guanine, cytosine, and thymine, in a molecule of DNA....
 analysis.

Russula Emetica
The following characteristics are often important in identifying individual species:
  • the exact colour of the spore powder (white/cream/ochre),
  • the taste (mild/bitter/acrid),
  • colour changes in the flesh,
  • the distance from the centre to which the cap skin can be pulled off: (peeling percentage).
  • cap colour (but this is often very variable within one species),
  • reaction of the flesh to ferrous sulphate
    Iron(II) sulfate

    Iron sulfate or ferrous sulfate is the chemical compound with the formula . It is most commonly encountered as the blue-green heptahydrate....
     (FeSO4), formalin, alkalis, and other chemicals,
  • ornamentation of the spores, and
  • other microscopic characteristics, such as the appearance of the cystidia
    Cystidium

    A cystidium is a relatively large cell found on the hymenium of a basidiomycete , often between clusters of basidium. Since cystidia have highly varied and distinct shapes that are often unique to a particular species or genus, they are a useful micromorphological characteristic in the identification of basidiomycetes....
     in various mounting reagents.


Despite the difficulty in positively identifying collected specimens, the possibility to spot the toxic species by their acrid taste makes some of the mild species, such as R. cyanoxantha
Russula cyanoxantha

Russula cyanoxantha, commonly known as the Charcoal burner, is a basidiomycete mushroom, distinguished from most other members of the Russula genus by the fact that its gill s do not split, but are soft and flexible....
 and R.. vesca
Russula vesca

Russula vesca, known by the common names of Bare-toothed russula or The Flirt, is a basidiomycete mushroom of the genus Russula....
, popular edible mushrooms. As far as is known, no species of Russula is deadly poisonous and mild-tasting ones are all edible. Note that this rule applies only to Russulas and not to other types of mushrooms! see http://www.mtsn.tn.it/russulales-news/pdf/macro_form.pdf

Toxicity

The main pattern of toxicity seen among Russula species to date has been gastrointestinal symptoms in those with a bitter taste when eaten raw or undercooked; many of these are red-capped species such as R. emetica
Russula emetica

Russula emetica, commonly known as The Sickener, is a basidiomycete mushroom of the genus Russula, two of many species with a predominantly red-coloured cap and white gills and stalk....
, R. sardonia
Russula sardonia

Russula sardonia, known as the The primrose brittlegill, is a mushroom of the Russula genus, which are commonly known as Brittle Gills....
 and R. nobilis. However, rhabdomyolysis
Rhabdomyolysis

Rhabdomyolysis is the rapid breakdown of skeletal muscle tissue due to injury to muscle tissue. The muscle damage may be caused by physical , chemical, or biological factors....
 was seen after consumption of R. subnigricans
Russula subnigricans

Russula subnigricans is a basidiomycete mushroom of the genus Russula found in China and North America. It has been responsible for mushroom poisoning in Taiwan....
 in Taiwan. Several active agents have been isolated; one designated russuphelin A by researchers in Japan.

Species

For more examples, see the List of Russula species
List of Russula species

This is a list of Russula species.* Russula acetolens* Russula acrifolia Henri Romagnesi* Russula adulterina* Russula adusta Elias Magnus Fries...
.
  • Edible Toxicity Icon
    Russula cyanoxantha
    Russula cyanoxantha

    Russula cyanoxantha, commonly known as the Charcoal burner, is a basidiomycete mushroom, distinguished from most other members of the Russula genus by the fact that its gill s do not split, but are soft and flexible....
     - one of the largest species, with blue to greenish cap, mild taste and white, greasy gills.
  • Poisonous Toxicity Icon
    Russula emetica
    Russula emetica

    Russula emetica, commonly known as The Sickener, is a basidiomycete mushroom of the genus Russula, two of many species with a predominantly red-coloured cap and white gills and stalk....
     - so acrid it can be dried and powdered to make a chilli pepper substitute;
  • Poisonous Toxicity Icon
    Russula subnigricans
    Russula subnigricans

    Russula subnigricans is a basidiomycete mushroom of the genus Russula found in China and North America. It has been responsible for mushroom poisoning in Taiwan....
     - a poisonous mushroom causing rhabdomyolysis
    Rhabdomyolysis

    Rhabdomyolysis is the rapid breakdown of skeletal muscle tissue due to injury to muscle tissue. The muscle damage may be caused by physical , chemical, or biological factors....
     in Taiwan
    Taiwan

    Taiwan is an island in East Asia. "Taiwan" is also commonly used to refer to the country governed by the Republic of China and to the ROC itself, which governs the island of Taiwan, Orchid Island and Green Island, Taiwan in the Pacific Ocean off the Taiwan coast, the Penghu islands in the Taiwan Strait, and Kinmen and the Matsu Islands...
    .
  • Edible Toxicity Icon
    Russula virescens
    Russula virescens

    Russula virescens is a basidiomycete mushroom of the genus Russula, sometimes called the Green-cracking russula....
     - an excellent mushroom, easily recognizable by the green and distinctly crackled cap cuticle;
  • Choice Toxicity Icon
    Russula xerampelina
    Russula xerampelina

    Russula xerampelina, also known commonly as the Shrimp Mushroom, or Crab Brittlegill, is a basidiomycete mushroom of the brittlegill genus Russula....
     - an edible russula that smells and tastes like shrimp or seafood;


See also

  • Mushroom hunting
    Mushroom hunting

    Mushroom hunting, mushrooming, mushroom picking and similar terms describe the activity of hunter-gatherer mushrooms in the wild, typically for eating....
  • Mushroom poisoning
    Mushroom poisoning

    Mushroom poisoning, also known as mycetism, refers to deleterious effects from ingestion of toxic substances present in a mushroom. These symptoms can vary from slight Gastrointestinal tract discomfort to death....


External links

  • Russulales News
  • Genus Russula at Mushroom Expert.com