Misplaced Pages

#637362

54-477: 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 mushroom collectors. Their distinguishing characteristics include usually brightly coloured caps, a white to dark yellow spore print , brittle, attached gills , an absence of latex , and absence of partial veil or volva tissue on

108-446: A distinctive flesh consistency , 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. Hence the genus Russula is sometimes known colloquially as "brittle gills". They have splitting gills and do not exude

162-447: A genus in his 1821 work The Natural Arrangement of British Plants . The name Russula is derived from the Latin word russus , meaning "red". "If we know of any one, who in the pride of intellect spurned all mental tasks as mere play, we would tame him by insisting on his mastering, classifying and explaining the synonyms of the genus Russula ." Like the genus Lactarius , russulas have

216-643: A later homonym of a validly published name is a nomen illegitimum or nom. illeg. ; for a full list refer to the International Code of Nomenclature for algae, fungi, and plants and the work cited above by Hawksworth, 2010. In place of the "valid taxon" in zoology, the nearest equivalent in botany is " correct name " or "current name" which can, again, differ or change with alternative taxonomic treatments or new information that results in previously accepted genera being combined or split. Prokaryote and virus codes of nomenclature also exist which serve as

270-621: A long time and redescribed as new by a range of subsequent workers, or if a range of genera previously considered separate taxa have subsequently been consolidated into one. For example, the World Register of Marine Species presently lists 8 genus-level synonyms for the sperm whale genus Physeter Linnaeus, 1758, and 13 for the bivalve genus Pecten O.F. Müller, 1776. Within the same kingdom, one generic name can apply to one genus only. However, many names have been assigned (usually unintentionally) to two or more different genera. For example,

324-426: A milky substance at cut surfaces, contrary to the genus Lactarius . Presence of large spherical cells, 'sphaerocysts', in the stipe is an important characteristic feature to distinguish the members of Russulaceae from other mushrooms. In Russula , the stipe breaks like the flesh of an apple, while in most other families it only breaks into fibres. The spore powder varies from white to cream, or even orange. While it

378-409: A reference for designating currently accepted genus names as opposed to others which may be either reduced to synonymy, or, in the case of prokaryotes, relegated to a status of "names without standing in prokaryotic nomenclature". An available (zoological) or validly published (botanical) name that has been historically applied to a genus but is not regarded as the accepted (current/valid) name for

432-434: A small range of fungal hosts, all of them members of Russulaceae , including 18 species of Russula . Russula fruit bodies provide a seasonal food source for slugs , squirrels and deer . Some russulas can bioaccumulate high levels of toxic metals from their environment. For example, Russula atropurpurea is capable of concentrating zinc , a property attributed to the presence of metallothionein -like peptides in

486-440: A supplementary food supply. There are also plants, such as some orchid species, that are non-photosynthetic and obligately myco-heterotrophic for part of their life cycle , and photosynthetic and facultatively myco-heterotrophic or non-myco-heterotrophic for the rest of their life cycle. Not all non-photosynthetic or " achlorophyllous " plants are myco-heterotrophic – some non-photosynthetic plants like dodder directly parasitize

540-488: A synonym of Russula but is still in use. Genus The composition of a genus is determined by taxonomists . The standards for genus classification are not strictly codified, so different authorities often produce different classifications for genera. There are some general practices used, however, including the idea that a newly defined genus should fulfill these three criteria to be descriptively useful: Moreover, genera should be composed of phylogenetic units of

594-427: A taxon; however, the names published in suppressed works are made unavailable via the relevant Opinion dealing with the work in question. In botany, similar concepts exist but with different labels. The botanical equivalent of zoology's "available name" is a validly published name . An invalidly published name is a nomen invalidum or nom. inval. ; a rejected name is a nomen rejiciendum or nom. rej. ;

SECTION 10

#1733093498638

648-455: A total of c. 520,000 published names (including synonyms) as at end 2019, increasing at some 2,500 published generic names per year. "Official" registers of taxon names at all ranks, including genera, exist for a few groups only such as viruses and prokaryotes, while for others there are compendia with no "official" standing such as Index Fungorum for fungi, Index Nominum Algarum and AlgaeBase for algae, Index Nominum Genericorum and

702-725: Is a popular edible throughout Asia, Europe, and the Pacific. In Finland, commonly eaten species include (but are not limited to) Russula vinosa , Russula vesca , Russula paludosa , Russula decolorans , Russula xerampelina and Russula claroflava . In Thailand, russulas collected by locals and sold in roadsides and local markets include Russula alboareolata , Russula lepida , Russula nigricans , Russula virescens , and Russula xerampelina . Edible russulas in Nepal include Russula flavida and Russula chlorides . The tropical Chinese species Russula griseocarnosa , misidentified as

756-425: Is also used for plants that engage in mutualistic mycorrhizal relationships. Full (or obligate) myco-heterotrophy exists when a non-photosynthetic plant (a plant largely lacking in chlorophyll or otherwise lacking a functional photosystem ) gets all of its food from the fungi that it parasitizes. Partial (or facultative) myco-heterotrophy exists when a plant is capable of photosynthesis, but parasitizes fungi as

810-596: Is discouraged by both the International Code of Zoological Nomenclature and the International Code of Nomenclature for algae, fungi, and plants , there are some five thousand such names in use in more than one kingdom. For instance, A list of generic homonyms (with their authorities), including both available (validly published) and selected unavailable names, has been compiled by the Interim Register of Marine and Nonmarine Genera (IRMNG). The type genus forms

864-475: Is mostly free of deadly poisonous species, and mild-tasting ones are all edible. All Russula species are ectomycorrhizal symbionts with higher plants and trees, and the genus has a collectively diverse host range. Some species are cosmopolitan and capable of forming associations with one or more hosts in a range of habitats, while others are more constrained in either host or habitat or both. The mycoheterotrophic plant Monotropa uniflora associates with

918-471: Is now known that these plants are not physiologically capable of directly breaking down organic matter and that in order to get food, non-photosynthetic plants must engage in parasitism, either through myco-heterotrophy or direct parasitism of other plants. The interface between the plant and fungal partners in this association is between the roots of the plant and the mycelium of the fungus. Myco-heterotrophy therefore closely resembles mycorrhiza (and indeed

972-415: 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

1026-460: Is somewhat arbitrary. Although all species within a genus are supposed to be "similar", there are no objective criteria for grouping species into genera. There is much debate among zoologists about whether enormous, species-rich genera should be maintained, as it is extremely difficult to come up with identification keys or even character sets that distinguish all species. Hence, many taxonomists argue in favor of breaking down large genera. For instance,

1080-474: Is the type species , and the generic name is permanently associated with the type specimen of its type species. Should the specimen turn out to be assignable to another genus, the generic name linked to it becomes a junior synonym and the remaining taxa in the former genus need to be reassessed. In zoological usage, taxonomic names, including those of genera, are classified as "available" or "unavailable". Available names are those published in accordance with

1134-520: Is the most commonly consumed and economically important mushroom genus in Madagascar , particularly Russula prolifica and Russula edulis . This and other edible Russula are typically stripped of their cap cuticle before selling to make them more similar in appearance to the Agaricus bisporus . In Tanzania , Russula cellulata and Russula ciliata are sometimes used as food. Russula cyanoxantha

SECTION 20

#1733093498638

1188-588: Is the non-photosynthetic liverwort Aneura mirabilis (previously considered a species of Cryptothallus ). Partial myco-heterotrophy is common in the Gentian family , with a few genera such as Voyria being fully myco-heterotrophic; in photosynthetic orchids; and in a number of other plant groups. Some ferns and clubmosses have myco-heterotrophic gametophyte stages. The fungi that are parasitized by myco-heterotrophs are typically fungi with large energy reserves to draw on, usually mycorrhizal fungi, though there

1242-556: Is thought to have evolved from mycorrhiza), except that in myco-heterotrophy, the flow of carbon is from the fungus to the plant, rather than vice versa. Most myco-heterotrophs can therefore be seen as ultimately being epiparasites , since they take energy from fungi that in turn get their energy from vascular plants . Indeed, much myco-heterotrophy takes place in the context of common mycorrhizal networks , in which plants use mycorrhizal fungi to exchange carbon and nutrients with other plants. In these systems, myco-heterotrophs play

1296-621: The International Code of Zoological Nomenclature ; the earliest such name for any taxon (for example, a genus) should then be selected as the " valid " (i.e., current or accepted) name for the taxon in question. Consequently, there will be more available names than valid names at any point in time; which names are currently in use depending on the judgement of taxonomists in either combining taxa described under multiple names, or splitting taxa which may bring available names previously treated as synonyms back into use. "Unavailable" names in zoology comprise names that either were not published according to

1350-799: The International Plant Names Index for plants in general, and ferns through angiosperms, respectively, and Nomenclator Zoologicus and the Index to Organism Names for zoological names. Totals for both "all names" and estimates for "accepted names" as held in the Interim Register of Marine and Nonmarine Genera (IRMNG) are broken down further in the publication by Rees et al., 2020 cited above. The accepted names estimates are as follows, broken down by kingdom: The cited ranges of uncertainty arise because IRMNG lists "uncertain" names (not researched therein) in addition to known "accepted" names;

1404-419: The nomenclature codes , which allow each species a single unique name that, for animals (including protists ), plants (also including algae and fungi ) and prokaryotes ( bacteria and archaea ), is Latin and binomial in form; this contrasts with common or vernacular names , which are non-standardized, can be non-unique, and typically also vary by country and language of usage. Except for viruses ,

1458-404: The platypus belongs to the genus Ornithorhynchus although George Shaw named it Platypus in 1799 (these two names are thus synonyms ) . However, the name Platypus had already been given to a group of ambrosia beetles by Johann Friedrich Wilhelm Herbst in 1793. A name that means two different things is a homonym . Since beetles and platypuses are both members of the kingdom Animalia,

1512-431: The vascular tissue of other plants. The partial or full loss of photosynthesis is reflected by extreme physical and functional reductions of plastid genomes in mycoheterophic plants, an ongoing evolutionary process. In the past, non-photosynthetic plants were mistakenly thought to get food by breaking down organic matter in a manner similar to saprotrophic fungi. Such plants were therefore called " saprophytes ". It

1566-471: The European R. vinosa until 2009, is commercially collected as food and medicine. The main pattern of toxicity seen among Russula species to date has been gastrointestinal symptoms in those with a spicy (acrid) taste when eaten raw or undercooked; many of these are red-capped species such as R. emetica , R. sardonia and R. nobilis . The Asian species Russula subnigricans has been

1620-442: The base for higher taxonomic ranks, such as the family name Canidae ("Canids") based on Canis . However, this does not typically ascend more than one or two levels: the order to which dogs and wolves belong is Carnivora ("Carnivores"). The numbers of either accepted, or all published genus names is not known precisely; Rees et al., 2020 estimate that approximately 310,000 accepted names (valid taxa) may exist, out of

1674-560: The cause of several fatal cases of rhabdomyolysis in Japan. Several active agents have been isolated from the species, including russuphelin A and cycloprop-2-ene carboxylic acid . Despite the large number of species, the secondary metabolites of Russula have not been well investigated, especially compared to Lactarius . Russula foetens was shown to produce the marasmane sesquiterpenes Lactapiperanol A and Lactapiperanol E . A novel lectin with potent in vitro antitumor activity

Russula - Misplaced Pages Continue

1728-514: The defining characteristics to be the fleshy fruit bodies , depressed cap , and equal gills . He reduced it to the rank of tribe in the genus Agaricus in 1801. Elias Fries similarly regarded Russula as a tribe of Agaricus in his influential Systema Mycologicum (1821), but later (1825) raised it to the rank of genus in the Systema Orbis Vegetabilis . Around the same time, Samuel Frederick Gray also recognized Russula as

1782-446: The form "author, year" in zoology, and "standard abbreviated author name" in botany. Thus in the examples above, the genus Canis would be cited in full as " Canis Linnaeus, 1758" (zoological usage), while Hibiscus , also first established by Linnaeus but in 1753, is simply " Hibiscus L." (botanical usage). Each genus should have a designated type , although in practice there is a backlog of older names without one. In zoology, this

1836-727: The generic name (or its abbreviated form) still forms the leading portion of the scientific name, for example, Canis lupus lupus for the Eurasian wolf subspecies, or as a botanical example, Hibiscus arnottianus ssp. immaculatus . Also, as visible in the above examples, the Latinised portions of the scientific names of genera and their included species (and infraspecies, where applicable) are, by convention, written in italics . The scientific names of virus species are descriptive, not binomial in form, and may or may not incorporate an indication of their containing genus; for example,

1890-994: The genus. In contrast, European field guides have a more favorable opinion and list more edible species. In the Pacific Northwest region of North America, only Russula brevipes parasitized with Hypomyces lactifluorum —known as lobster mushroom—is collected commercially. Several Russula species are sold in the markets of Izta-Popo Zoquiapan National Park (central Mexico): R. brevipes , R. cyanoxantha , R. mexicana and R. olivacea . In Tlaxcala , wild species sold in market include R. alutacea , R. cyanoxantha , R. delica , R. mariae , R. olivacea , R. romagnesia , and R. xerampelina . In Madagascar, species collected from introduced eucalypt forests include Russula madecassense , Russula prolifica , and several other species of minor importance, including some that have not yet been officially described. Russula

1944-628: The largest component, with 23,236 ± 5,379 accepted genus names, of which 20,845 ± 4,494 are angiosperms (superclass Angiospermae). By comparison, the 2018 annual edition of the Catalogue of Life (estimated >90% complete, for extant species in the main) contains currently 175,363 "accepted" genus names for 1,744,204 living and 59,284 extinct species, also including genus names only (no species) for some groups. The number of species in genera varies considerably among taxonomic groups. For instance, among (non-avian) reptiles , which have about 1180 genera,

1998-454: The lizard genus Anolis has been suggested to be broken down into 8 or so different genera which would bring its ~400 species to smaller, more manageable subsets. Mycoheterotrophic Myco-heterotrophy (from Greek μύκης mýkes ' fungus ' , ἕτερος héteros ' another ' , ' different ' and τροφή trophé ' nutrition ' ) is a symbiotic relationship between certain kinds of plants and fungi , in which

2052-403: The most (>300) have only 1 species, ~360 have between 2 and 4 species, 260 have 5–10 species, ~200 have 11–50 species, and only 27 genera have more than 50 species. However, some insect genera such as the bee genera Lasioglossum and Andrena have over 1000 species each. The largest flowering plant genus, Astragalus , contains over 3,000 species. Which species are assigned to a genus

2106-453: The mushroom. Russula nigricans can accumulate lead to a level up to five times more concentrated than the soil it grows in, while R. ochroleuca concentrates environmental mercury . Humans collect several species of Russula for food. There is a cultural divide toward interpretation of Russula edibility. In general, North American field guides tend to list mostly non-edible species and advise caution when consuming any member of

2160-428: The name could not be used for both. Johann Friedrich Blumenbach published the replacement name Ornithorhynchus in 1800. However, a genus in one kingdom is allowed to bear a scientific name that is in use as a generic name (or the name of a taxon in another rank) in a kingdom that is governed by a different nomenclature code. Names with the same form but applying to different taxa are called "homonyms". Although this

2214-409: The plant gets all or part of its food from parasitism upon fungi rather than from photosynthesis . A myco-heterotroph is the parasitic plant partner in this relationship. Myco-heterotrophy is considered a kind of cheating relationship and myco-heterotrophs are sometimes informally referred to as " mycorrhizal cheaters ". This relationship is sometimes referred to as mycotrophy , though this term

Russula - Misplaced Pages Continue

2268-434: The professional mycological community, and may ultimately depend on DNA sequencing analysis. The following characteristics are often important in identifying individual species: 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 and R. vesca , popular edible mushrooms. Russula

2322-526: The provisions of the ICZN Code, e.g., incorrect original or subsequent spellings, names published only in a thesis, and generic names published after 1930 with no type species indicated. According to "Glossary" section of the zoological Code, suppressed names (per published "Opinions" of the International Commission of Zoological Nomenclature) remain available but cannot be used as the valid name for

2376-988: The role of "mycorrhizal cheaters", taking carbon from the common network, with no known reward. A special form of mycoheterotrophic association, which appears to be a chimera between the haustorial parasitism of a parasitic plant and mycoheterotrophy, is observed in Parasitaxus usta , the only mycoheterotrophic gymnosperm . In congruence with older reports, it has been recently shown that some myco-heterotrophic orchids can be supported by saprotrophic fungi, exploiting litter- or wood-decaying fungi. In addition, several green plants (evolutionarily close to myco-heterotrophic species) have been shown to engage in partial myco-heterotrophy, that is, they are able to take carbon from mycorrhizal fungi, in addition to their photosynthetic intake. Myco-heterotrophs are found among several plant groups, mainly flowering plants . All monotropes and non-photosynthetic orchids are full myco-heterotrophs, as

2430-466: The same kind as other (analogous) genera. The term "genus" comes from Latin genus , a noun form cognate with gignere ('to bear; to give birth to'). The Swedish taxonomist Carl Linnaeus popularized its use in his 1753 Species Plantarum , but the French botanist Joseph Pitton de Tournefort (1656–1708) is considered "the founder of the modern concept of genera". The scientific name (or

2484-408: The scientific epithet) of a genus is also called the generic name ; in modern style guides and science, it is always capitalised. It plays a fundamental role in binomial nomenclature , the system of naming organisms , where it is combined with the scientific name of a species : see Botanical name and Specific name (zoology) . The rules for the scientific names of organisms are laid down in

2538-497: The specific name particular to the wolf. A botanical example would be Hibiscus arnottianus , a particular species of the genus Hibiscus native to Hawaii. The specific name is written in lower-case and may be followed by subspecies names in zoology or a variety of infraspecific names in botany . When the generic name is already known from context, it may be shortened to its initial letter, for example, C. lupus in place of Canis lupus . Where species are further subdivided,

2592-412: The standard format for a species name comprises the generic name, indicating the genus to which the species belongs, followed by the specific epithet, which (within that genus) is unique to the species. For example, the gray wolf 's scientific name is Canis lupus , with Canis ( Latin for 'dog') being the generic name shared by the wolf's close relatives and lupus (Latin for 'wolf') being

2646-454: The stem. Microscopically, the genus is characterised by the amyloid ornamented spores and flesh (trama) composed of spherocysts. Members of the related genus Lactarius have similar characteristics but emit a milky latex when their gills are broken. The genus was described by Christian Hendrik Persoon in 1796. Christian Hendrik Persoon first circumscribed the genus Russula in his 1796 work Observationes Mycologicae , and considered

2700-403: The taxon is termed a synonym ; some authors also include unavailable names in lists of synonyms as well as available names, such as misspellings, names previously published without fulfilling all of the requirements of the relevant nomenclatural code, and rejected or suppressed names. A particular genus name may have zero to many synonyms, the latter case generally if the genus has been known for

2754-566: The values quoted are the mean of "accepted" names alone (all "uncertain" names treated as unaccepted) and "accepted + uncertain" names (all "uncertain" names treated as accepted), with the associated range of uncertainty indicating these two extremes. Within Animalia, the largest phylum is Arthropoda , with 151,697 ± 33,160 accepted genus names, of which 114,387 ± 27,654 are insects (class Insecta). Within Plantae, Tracheophyta (vascular plants) make up

SECTION 50

#1733093498638

2808-429: The virus species " Salmonid herpesvirus 1 ", " Salmonid herpesvirus 2 " and " Salmonid herpesvirus 3 " are all within the genus Salmonivirus ; however, the genus to which the species with the formal names " Everglades virus " and " Ross River virus " are assigned is Alphavirus . As with scientific names at other ranks, in all groups other than viruses, names of genera may be cited with their authorities, typically in

2862-673: Was isolated from Russula rosea , the first lectin reported from a Russula . This mushroom is also the source of the sesquiterpenes rulepidanol and rulepidadienes A and B. Russula nigricans contains the compound nigricanin, the first ellagic acid derivative isolated from higher fungi. The description of Russula was changed in 2007 when molecular analysis revealed that several sequestrate species formerly classified in Macowanites (syn. Elasmomyces ) were shown to lie within Russula . The type species of Macowanites , Macowanites agaricinus ,

2916-412: Was transferred and several new species were added: Russula albidoflava , R. albobrunnea , R. brunneonigra , R. galbana , R. pumicoidea , R. reddellii , R. sinuata , and R. variispora . The genus names Gymnomyces and Martellia , formerly used for sequestrate species, are now accepted synonyms of Russula , The genus Cystangium is also probably

#637362