Editing Genus (section)

==Use==
The scientific name (or 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 [[organism]]s, where it is combined with the scientific name of a [[species]]: see [[Botanical name]] and [[Specific name (zoology)]].<ref>{{cite book |author=International Commission on Zoological Nomenclature |author-link= |date=1999 |title=International Code of Zoological Nomenclature |url=https://www.iczn.org/the-code/the-code-online/ |location=London |publisher=The International Trust for Zoological Nomenclature |page= |isbn=0-85301-006-4 |access-date=2023-11-10 |archive-date=2021-09-03 |archive-url=https://web.archive.org/web/20210903062842/https://www.iczn.org/the-code/the-code-online/ |url-status=live }}</ref><ref>{{cite web |url=http://www.iapt-taxon.org/nomen/main.php?page=art3 |title=International Code of Nomenclature for algae, fungi, and plants – Melbourne Code |date=2012 |website=IAPT-Taxon.org |access-date=2023-11-10 |archive-date=2020-10-10 |archive-url=https://web.archive.org/web/20201010230658/https://www.iapt-taxon.org/nomen/main.php?page=art3 |url-status=live }}</ref>

=== Use in nomenclature ===
{{Main|Binomial nomenclature|Taxonomy (biology)|Author citation (zoology)|Author citation (botany)}}
The rules for the [[scientific name]]s of [[organism]]s are laid down in the [[Nomenclature Codes|nomenclature codes]], which allow each species a single unique name that, for [[animal]]s (including [[protist]]s), [[plant]]s (also including [[algae]] and [[Fungus|fungi]]) and [[prokaryote]]s ([[bacteria]] and [[archaea]]), is [[Latin]] and binomial in form; this contrasts with [[common name|common or vernacular names]], which are non-standardized, can be non-unique, and typically also vary by country and language of usage.

Except for [[Virus classification|viruses]], 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 {{nowrap|''{{lang|la|Canis lupus}}'',}} with ''[[Canis]]'' ([[Latin]] for 'dog') being the generic name shared by the wolf's close relatives and {{lang|la|lupus}} (Latin for 'wolf') being 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 name]]s 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, the generic name (or its abbreviated form) still forms the leading portion of the scientific name, for example, {{nowrap|''{{lang|la|Canis lupus lupus}}''}} for the [[Eurasian wolf]] subspecies, or as a botanical example, {{nowrap|''{{lang|la|Hibiscus arnottianus}}'' ssp. ''{{lang|la|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 [[Italic type|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, 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 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 [[Carl Linnaeus|Linnaeus]] but in 1753, is simply "''Hibiscus'' L." (botanical usage).

===The type concept===
{{see also|Type genus|Type species|Type specimen}}
Each genus should have a designated [[type (biology)|type]], although in practice there is a backlog of older names without one. In zoology, this 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 [[taxon|taxa]] in the former genus need to be reassessed.

===Categories of generic name===
In zoological usage, taxonomic names, including those of genera, are classified as "available" or "unavailable". Available names are those published in accordance with the [[International Code of Zoological Nomenclature]]; the earliest such name for any taxon (for example, a genus) should then be selected as the "[[valid name (zoology)|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 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.<ref name="Hawksworth2010">{{cite book|author=D. L. Hawksworth|title=Terms Used in Bionomenclature: The Naming of Organisms and Plant Communities : Including Terms Used in Botanical, Cultivated Plant, Phylogenetic, Phytosociological, Prokaryote (bacteriological), Virus, and Zoological Nomenclature|url=https://books.google.com/books?id=Qky7_6-UcQQC&pg=PA10|year=2010|publisher=GBIF|isbn=978-87-92020-09-3|pages=1–215}}</ref> 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 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 {{Lang|la|nomen invalidum}} or {{Lang|la|nom. inval.}}; a rejected name is a {{Lang|la|nomen rejiciendum}} or {{Lang|la|nom. rej.}}; a later homonym of a validly published name is a {{Lang|la|nomen illegitimum}} or {{Lang|la|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.<ref name="Hawksworth2010" /> 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.

[[International Code of Nomenclature of Prokaryotes|Prokaryote]] and [[International Committee on Taxonomy of Viruses|virus]] codes of nomenclature also exist which serve as a reference for designating currently{{When|date=August 2023}} 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 the taxon is termed a [[synonym (taxonomy)|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 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,<ref>{{Cite web|url=http://www.marinespecies.org/aphia.php?p=taxdetails&id=137032|title=WoRMS - World Register of Marine Species - Physeter Linnaeus, 1758|website=www.marinespecies.org|access-date=2018-06-02|archive-date=2017-07-09|archive-url=https://web.archive.org/web/20170709213325/http://www.marinespecies.org/aphia.php?p=taxdetails&id=137032|url-status=live}}</ref> and 13 for the bivalve genus ''[[Pecten (bivalve)|Pecten]]'' O.F. Müller, 1776.<ref>{{Cite web|url=http://www.marinespecies.org/aphia.php?p=taxdetails&id=138323|title=WoRMS - World Register of Marine Species - Pecten O. F. Müller, 1776|website=www.marinespecies.org|access-date=2018-06-02|archive-date=2018-08-10|archive-url=https://web.archive.org/web/20180810174658/http://www.marinespecies.org/aphia.php?p=taxdetails|url-status=live}}</ref>

===Identical names (homonyms)===
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, the [[platypus]] belongs to the genus ''Ornithorhynchus'' although [[George Shaw (biologist)|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 beetle]]s 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, the name could not be used for both. [[Johann Friedrich Blumenbach]] published the replacement name ''Ornithorhynchus'' in 1800.

However, a genus in one [[kingdom (biology)|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 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,
* ''[[Anura (frog)|Anura]]'' is the name of the [[order (biology)|order]] of frogs but also is the name of a [[synonym (botany)|non-current]] genus of plants;
* ''Aotus'' is the generic name of both [[Aotus (plant)|golden peas]] and [[night monkey]]s;
* ''Oenanthe'' is the generic name of both [[wheatear]]s and [[Oenanthe (plant)|water dropwort]]s;
* ''Prunella'' is the generic name of both [[accentor]]s and [[self-heal]]; and
* ''Proboscidea'' is the order of [[elephant]]s and the genus of [[Proboscidea (plant)|devil's claws]].
* The name of the genus ''[[Paramecia (alga)|Paramecia]]'' (an extinct red alga) is also the plural of the name of the genus ''[[Paramecium]]'' (which is in the SAR supergroup), which can also lead to confusion.
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).<ref name ="IRMNG">{{Cite web|url=http://www.irmng.org/homonyms.php|title=IRMNG: Interim Register of Marine and Nonmarine Genera|website=www.irmng.org|access-date=2016-11-17|archive-date=2016-11-17|archive-url=https://web.archive.org/web/20161117212132/http://www.irmng.org/homonyms.php|url-status=live}}</ref>

===Use in higher classifications===
The [[type genus]] forms the base for higher [[Taxonomy (biology)|taxonomic]] ranks, such as the family name {{lang|la|[[Canidae]]}} ("Canids") based on ''Canis''. However, this does not typically ascend more than one or two levels: the [[order (biology)|order]] to which dogs and wolves belong is {{lang|la|[[Carnivora]]}} ("Carnivores").