Content deleted Content added
better grammar in intro |
m Reverted 1 edit by 203.170.9.245 (talk) to last revision by 2001:5A8:601A:2200:2C:6489:A8AE:87C3 |
||
Line 1:
{{short description|Species naming system}}
{{redirect|Latin name|personal names in the Roman Empire|Roman naming conventions|the practice of rendering names in a Latin style|Latinisation of names}}
{{use dmy dates|date=January 2018}}
[[File:Killerwhales jumping.jpg|thumb|''[[Orcinus orca]]'', the orca or the killer whale]]
[[File:Starr 070320-5799 Echinopsis pachanoi.jpg|thumb|[[Trichocereus macrogonus var. pachanoi|''Trichocereus macrogonus'' var. ''pachanoi'']], the San Pedro cactus]]
In [[Taxonomy (biology)|taxonomy]], '''binomial nomenclature''' ("two-term naming system"), also called '''binary nomenclature''', is a formal system of naming [[species]] of living things by giving each a name composed of two parts, both of which use [[Latin grammar|Latin grammatical forms]], although they can be based on words from other languages. Such a name is called a '''binomial name''' (often shortened to just "binomial"), a '''binomen''',<ref name="ICZN1999_Glossary"/> '''{{not a typo|binominal|reason="Binomi'n'al", with an "n" before the "al", is the alternative name in the ICZN. Do not "correct" it.}} name''', or a '''scientific name'''; more informally, it is also called a '''Latin name'''. In the [[International Code of Zoological Nomenclature]] (ICZN), the system is also called '''{{not a typo|binominal|reason="Binomi'n'al", with an "n" before the "al", is the alternative name in the ICZN. Do not "correct" it.}} nomenclature''',<ref name="ICZN1999_Chap2Article5"/> with an "n" before the "al" in "binominal", which is {{em|not}} a typographic error,<!--Keep the text explaining that "binomiNal" is NOT a typo or redundant, and do not hide it inside a footnote. Even with the big {{not a typo}} template, people just keep removing "binomiNal", such as in [[Special:Diff/1011109157]], [[Special:Diff/1147038384]], and [[Special:Diff/1183771307]]. Note that italicizing and underscoring the "N" both failed to prevent the removals. They got removed as "typos", instead.--> meaning "two-name naming system".<ref name="ICZN1999_Glossary"/>
The first part of the name – the ''[[generic name (biology)|generic name]]'' – identifies the [[genus]] to which the species belongs, whereas the second part – the '''specific name''' or '''specific epithet''' – distinguishes the species within the genus. For example, modern humans belong to the genus ''[[Homo]]'' and within this genus to the species ''[[Homo sapiens]]''. ''[[Tyrannosaurus rex]]'' is likely the most widely known binomial.<ref>{{cite book |last1=Busby |first1=Arthur III |display-authors=etal |title=A Guide to Rocks and Fossils |page=103 |date=1997}}</ref> The ''formal'' introduction of this system of naming species is credited to [[Carl Linnaeus]], effectively beginning with his work ''[[Species Plantarum]]'' in 1753.<ref name="Knapp" /> But as early as 1622, [[Gaspard Bauhin]] introduced in his book ''Pinax theatri botanici'' (English, ''Illustrated exposition of plants'') containing many names of genera that were later adopted by Linnaeus.<ref>{{cite web |last1=Bauhin |first1=Gaspard |title=Pinax theatri botanici |url=http://edb.kulib.kyoto-u.ac.jp/exhibit-e/b07/b07cont.html |publisher=Kyoto University Library |access-date=19 June 2016 |archive-date=17 October 2016 |archive-url=https://web.archive.org/web/20161017200341/http://edb.kulib.kyoto-u.ac.jp/exhibit-e/b07/b07cont.html |url-status=live}}</ref> Binomial nomenclature was introduced in order to provide succinct, relatively stable and verifiable names that could be used and understood internationally, unlike [[common names]] which are usually different in every language.<ref name="Stearn">{{Cite journal |date=1959 |title=The Background of Linnaeus's Contributions to the Nomenclature and Methods of Systematic Biology |journal=Systematic Zoology |volume=8 |issue= 1|pages=4–22 |url= |access-date= |last1=Stearn |first1=William T.|doi=10.2307/2411603 |jstor=2411603 }}</ref>
The application of binomial nomenclature is now governed by various internationally agreed codes of rules, of which the two most important are the ''[[International Code of Zoological Nomenclature]]'' (''ICZN'') for animals and the ''[[International Code of Nomenclature for algae, fungi, and plants]]'' (''ICNafp'' or ''ICN''). Although the general principles underlying binomial nomenclature are common to these two codes, there are some differences in the terminology they use and their particular rules.
In modern usage, the first letter of the generic name is always capitalized in writing, while that of the specific epithet is not, even when derived from a [[proper noun]] such as the name of a person or place. Similarly, both parts are [[italicize]]d in normal text (or underlined in handwriting). Thus the binomial name of the annual phlox (named after botanist [[Thomas Drummond (botanist)|Thomas Drummond]]) is now written as ''[[Phlox drummondii]]''. Often, after a species name is introduced in a text, the generic name is abbreviated to the first letter in subsequent mentions (e.g., ''P. drummondii'').
In scientific works, the [[#Authority|authority]] for a binomial name is usually given, at least when it is first mentioned, and the year of publication may be specified.
* In [[zoology]]
** "''[[Patella vulgata]]'' Linnaeus, 1758". The name "Linnaeus" tells the reader who published the name and description for this species; 1758 is the year the name and original description were published (in this case, in the [[10th edition of Systema Naturae|10th edition of the book ''Systema Naturae'']]).
** "''[[Passer domesticus]]'' (Linnaeus, 1758)". The original name given by Linnaeus was ''Fringilla domestica''; the parentheses indicate that the species is now placed in a different genus. The ICZN does not require that the name of the person who changed the genus be given, nor the date on which the change was made, although nomenclatorial catalogs usually include such information.
* In [[botany]]
** "''[[Amaranthus retroflexus]]'' L." – "L." is the standard abbreviation used for "Linnaeus".
** "''[[Hyacinthoides italica]]'' (L.) Rothm." – Linnaeus first named this bluebell species ''Scilla italica''; Rothmaler transferred it to the genus ''Hyacinthoides''; the ''ICNafp'' does not require that the dates of either publication be specified.
== Etymology ==
The word ''binomial'' is composed of two elements: {{wikt-lang|la|bi-}} ([[Latin]] prefix meaning 'two') and {{lang|la|[[wikt:nomial|nomial]]}} (the [[adjective]] form of {{lang|la|nomen}}, Latin for 'name'). In Medieval Latin, the related word {{lang|la|binomium}} was used to signify one term in a binomial expression in mathematics.<ref>{{cite web |url=https://www.cnrtl.fr/definition/bin%C3%B4me |title=binôme |work=Le Trésor de la langue française informatisé |publisher=Centre National de Ressources Textuelles et Lexicales |archive-url=https://web.archive.org/web/20170606122907/http://www.cnrtl.fr/definition/bin%C3%B4me |archive-date=6 June 2017}}</ref> In fact, the Latin word {{lang|la|binomium}} may validly refer to either of the epithets in the binomial name, which can equally be referred to as a {{lang|la|binomen}} (pl. {{lang|la|binomina}}).<ref>{{Cite web |title=Definition of BINOMEN |url=https://www.merriam-webster.com/dictionary/binomen |access-date=2025-01-31 |website=www.merriam-webster.com |language=en}}</ref>
==History==
[[File:Carl von Linné.jpg|thumb|[[Carl Linnaeus]] (1707{{ndash}}1778), a Swedish botanist, physician, and zoologist, invented the modern system of binomial nomenclature]]
Before the adoption of the modern binomial system of naming species, a scientific name consisted of a generic name combined with a specific name that was from one to several words long. Together they formed a system of polynomial nomenclature.<ref name="Reddy2007">{{cite book |last=Reddy |first=S. M. |title=University botany: Angiosperms, plant embryology and plant physiology |url=https://books.google.com/books?id=SuQJeFkYoRIC&pg=PA34 |date=2007 |publisher=New Age International |isbn=978-81-224-1547-6 |page=34 |access-date=13 November 2019 |archive-date=2 February 2023 |archive-url=https://web.archive.org/web/20230202160908/https://books.google.com/books?id=SuQJeFkYoRIC&pg=PA34 |url-status=live}}</ref> These names had two separate functions: to designate or label the species, and to be a diagnosis or description. These two goals were eventually found to be incompatible.<ref name="Blunt2004">{{cite book |last=Blunt |first=Wilfrid |title=Linnaeus: The compleat naturalist |url=https://books.google.com/books?id=FRH_EMhQYhYC&pg=PA266 |date=2004 |publisher=Frances Lincoln Ltd |isbn=978-0-7112-2362-2 |page=266}}</ref> In a simple genus that contained few species, it was easy to tell them apart with a one-word genus and a one-word specific name; but as more species were discovered, the names necessarily became longer and unwieldy—for instance, ''Plantago foliis ovato-lanceolatus pubescentibus, spica cylindrica, scapo tereti'' ("plantain with pubescent ovate-lanceolate leaves, a cylindric spike and a [[terete]] [[scape (botany)|scape]]"), which we know today as ''[[Plantago media]]''.<ref>{{Cite book |last=Linné |first=Carl von |url=https://www.biodiversitylibrary.org/page/26068083 |title=Species plantarum: exhibentes plantas rite cognitas ad genera relatas, cum diferentiis specificis, nominibus trivialibus, synonymis selectis, locis natalibus, secundum systema sexuale digestas |date=1753 |publisher=Junk |volume=1 |___location=Berlin}}</ref>
Such "polynomial names" may sometimes look like binomials, but are different. For example, Gerard's herbal (as amended by Johnson) describes various kinds of spiderwort: "The first is called ''Phalangium ramosum'', Branched Spiderwort; the second, ''Phalangium non ramosum'', Unbranched Spiderwort. The other ... is aptly termed ''Phalangium Ephemerum Virginianum'', Soon-Fading Spiderwort of Virginia".<ref>{{cite book |first1=John |last1=Gerard |first2=Thomas |last2=Johnson |date=1636 |title=The Herball, or, Generall Historie of Plantes /gathered by John Gerarde of London, Master in Chirurgerie; very much enlarged and amended by Thomas Johnson, Citizen and Apothecarye of London |publisher=Adam Islip, Joice Norton and Richard Whitakers and the [[Biodiversity Heritage Library]] |url=https://www.biodiversitylibrary.org/item/33580#page/88/mode/1up |access-date=14 January 2018 |archive-date=11 October 2017 |archive-url=https://web.archive.org/web/20171011132117/https://www.biodiversitylibrary.org/item/33580#page/88/mode/1up |url-status=live}}</ref> The Latin phrases are short descriptions, rather than identifying labels.
The [[Bauhin]]s, in particular [[Gaspard Bauhin|Caspar Bauhin]] (1560–1624), took some important steps towards the binomial system by pruning the Latin descriptions, in many cases to two words.<ref name=JohnsonSmithStockdalev>{{cite book |last1=Johnson |first1=A. T. |last2=Smith |first2=H. A. |last3=Stockdale |first3=A. P. |date=2019 |title=Plant Names Simplified: Their Pronunciation Derivation & Meaning |___location=Sheffield, Yorkshire |publisher=5M Publishing |isbn=978-1-910455-06-7}}, p. v</ref> The adoption by biologists of a system of strictly binomial nomenclature is due to Swedish botanist and physician [[Carl Linnaeus]] (1707–1778). {{anchor|trivial name}} It was in his 1753 ''[[Species Plantarum]]'' that Linnaeus began consistently using a one-word '''trivial name''' ({{lang|la|nomen triviale}}) after a generic name (genus name) in a system of binomial nomenclature.<ref name="Polaszek2009">{{cite book |last=Polaszek |first=Andrew |title=Systema naturae 250: The Linnaean ark |url=https://books.google.com/books?id=ReWP31_IJSIC&pg=PA189 |date=2009 |publisher=CRC Press |isbn=978-1-4200-9501-2 |page=189}}</ref> Trivial names had already appeared in his ''[[Critica Botanica]]'' (1737) and ''[[Philosophia Botanica]]'' (1751). This trivial name is what is now known as a [[specific epithet (botany)|specific epithet]] (''ICNafp'') or [[specific name (zoology)|specific name]] (''ICZN'').<ref name="Polaszek2009"/> The Bauhins' genus names were retained in many of these, but the descriptive part was reduced to a single word.
Linnaeus's trivial names introduced the idea that the function of a name could simply be to give a species a unique label, meaning that the name no longer needed to be descriptive. Both parts could, for example, be derived from the names of people. Thus Gerard's ''Phalangium ephemerum virginianum'' became ''[[Tradescantia virginiana]]'', where the genus name honoured [[John Tradescant the Younger]],{{NoteTag|Some sources say that both John Tradescant the Younger and his father, [[John Tradescant the Elder]], were intended by Linnaeus.}} an English botanist and gardener.<ref>{{Harvnb|Hyam|Pankhurst|1995|p=502}}</ref> A bird in the parrot family was named ''[[red-breasted parakeet|Psittacus alexandri]]'', meaning "Alexander's parrot", after [[Alexander the Great]], whose armies introduced eastern parakeets to Greece.<ref>{{cite book |last=Jobling |first=James A. |date=2010 |title=Helm Dictionary of Scientific Bird Names |___location=London |publisher=Christopher Helm |isbn=978-1-4081-2501-4}}</ref> Linnaeus's trivial names were much easier to remember and use than the parallel polynomial names, and eventually replaced them.<ref name=Knapp>{{cite web |last=Knapp |first=Sandra |author-link=Sandra Knapp |title=What's in a name? A history of taxonomy: Linnaeus and the birth of modern taxonomy |publisher=[[Natural History Museum, London]] |work=NHM.ac.uk |url=http://www.nhm.ac.uk/nature-online/science-of-natural-history/taxonomy-systematics/history-taxonomy/session1/index.html |access-date=17 June 2011 |archive-url=https://web.archive.org/web/20141018181831/http://www.nhm.ac.uk/nature-online/science-of-natural-history/taxonomy-systematics/history-taxonomy/session1/index.html |archive-date=18 October 2014}}</ref>
==Value==
[[File:E coli at 10000x, original.jpg|thumb|The bacterium ''[[Escherichia coli]]'', commonly shortened to ''E. coli'']]
The value of the binomial nomenclature system derives primarily from its economy, its widespread use, and the uniqueness and stability of names that the Codes of [[Zoological nomenclature|Zoological]] and [[Botanical nomenclature|Botanical]], [[Bacterial nomenclature|Bacterial]] and [[Virus nomenclature|Viral]] Nomenclature provide:
* Economy. Compared to the polynomial system which it replaced, a binomial name is shorter and easier to remember.<ref name=Knapp/> It corresponds to the noun-adjective form many [[common name|vernacular names]] take to indicate a species within a group (for example, 'brown bear' to refer to a particular type of bear),<ref name="Stearn"/> as well as the widespread system of [[family name]] plus [[given name]](s) used to name people in many cultures.<ref name=JohnsonSmithStockdalev/>
* Widespread use. The binomial system of nomenclature is governed by international codes and is used by biologists worldwide.<ref name="van dyke">{{cite book |last=Van Dyke |first=Fred |date=2008 |chapter=Contemporary Issues of the Species Concept |title=Conservation biology: foundations, concepts, applications |page=86 |publisher=Springer |isbn=978-1-4020-6890-4 |chapter-url=https://books.google.com/books?id=Evh1UD3ZYWcC&pg=PA86 |access-date=20 June 2011}}</ref> A few binomials have also entered common speech, such as ''[[Homo sapiens]]'', ''[[E. coli]]'', ''[[Boa constrictor]]'', ''[[Tyrannosaurus rex]]'', and ''[[Aloe vera]]''.
* Uniqueness. Provided that taxonomists agree as to the limits of a species, it can have only one name that is correct under the appropriate [[nomenclature code]], generally the earliest published if two or more names are accidentally assigned to a species.<ref name="russel">{{Cite book |first1=Peter J. |last1=Russell |first2=Stephen L. |last2=Wolfe |first3=Paul E. |last3=Hertz |first4=Cecie |last4=Starr |title=The Linnaean System of Taxonomy |volume=2 |publisher=Cengage Learning |chapter=Species Concepts and Speciation |date=2007 |page=493 |isbn=978-0-495-01033-3 |chapter-url=https://books.google.com/books?id=7F9UlGYGr0sC&pg=PA493}}</ref> This means the species a binomial name refers to can be clearly identified, as compared to the common names of species which are usually different in every language.<ref name="Stearn" /> However, establishing that two names actually refer to the same species and then determining which has priority can sometimes be difficult, particularly if the species was named by biologists from different countries. Therefore, a species may have more than one regularly used name; all but one of these names are "[[synonym (taxonomy)|synonyms]]".<ref name="csv">{{Cite journal |date=2007 |title=General Principles of Taxonomy |journal=Competition Science Vision |volume=10 |issue=114 |pages=764–767 |url=https://books.google.com/books?id=0-cDAAAAMBAJ |access-date=20 June 2011 |last1=Darpan |first1=Pratiyogita}}</ref> Furthermore, within zoology or botany, each species name applies to only one species. If a name is used more than once, it is called a [[Homonym (biology)|homonym]].
[[File:Petirrojo (Erithacus rubecula superbus ) (6178023045).jpg|thumb|''[[European robin|Erithacus rubecula superbus]]'', the Tenerife robin or petirrojo]]
* Stability. Although stability is far from absolute, the procedures associated with establishing binomial names, such as the [[Priority (biology)|principle of priority]], tend to favor stability.<ref name="stevenson">{{Cite book |first=Joan C. |last=Stevenson |title=Dictionary of concepts in physical anthropology |publisher=Greenwood Publishing Group |date=1991 |page=53 |isbn=978-0-313-24756-9 |url=https://books.google.com/books?id=MvuHGhrr2ocC&pg=PA53}}</ref> For example, when species are transferred between genera (as not uncommonly happens as a result of new knowledge), the second part of the binomial is kept the same (unless it becomes a homonym). Thus, there is disagreement among botanists as to whether the genera ''[[Chionodoxa]]'' and ''[[Scilla]]'' are sufficiently different for them to be kept separate. Those who keep them separate give the plant commonly grown in gardens in Europe the name ''[[Chionodoxa siehei]]''; those who do not give it the name ''Scilla siehei''.<ref>{{cite web |last1=Dashwood |first1=Melanie |last2=Mathew |first2=Brian |date=2005 |title=Hyacinthaceae – little blue bulbs (RHS Plant Trials and Awards, Bulletin Number 11) |work=RHS.org.uk |publisher=Royal Horticultural Society |url=http://www.rhs.org.uk/getattachment/04d1dd16-01be-4c31-9510-8a081dfa23b0/Hyacinthaceae---Little-Blue-Bulbs-Bulletin.aspx |access-date=19 February 2011 |archive-url=https://web.archive.org/web/20110806123722/http://www.rhs.org.uk/getattachment/04d1dd16-01be-4c31-9510-8a081dfa23b0/Hyacinthaceae---Little-Blue-Bulbs-Bulletin.aspx |archive-date=6 August 2011}}</ref> The ''siehei'' element is constant. Similarly, if what were previously thought to be two distinct species are demoted to a lower rank, such as subspecies, the second part of the binomial name is retained as a trinomen (the third part of the new name). Thus, the Tenerife robin may be treated as a different species from the European robin, in which case its name is ''Erithacus superbus'', or as only a subspecies, in which case its name is ''Erithacus rubecula superbus''.<ref>{{cite journal |last1=Bergmann |first1=H. H. |last2=Schottler |first2=B. |date=2001 |title=Tenerife robin ''Erithacus (rubecula) superbus'' – a species of its own? |url=https://issuu.com/dutchbirding/docs/db_23_3_2001/26 |via=Issuu |journal=[[Dutch Birding]] |volume=23 |pages=140–146 |access-date=26 January 2018 |archive-date=7 May 2019 |archive-url=https://web.archive.org/web/20190507175340/https://issuu.com/dutchbirding/docs/db_23_3_2001/26 |url-status=live}}</ref> The ''superbus'' element of the name is constant, as are its authorship and year of publication.
==Problems==
Binomial nomenclature for species has the effect that when a species is moved from one genus to another, sometimes the specific name or epithet must be changed as well. This may happen because the specific name is already used in the new genus, or to [[Agreement (linguistics)#Gender|agree in gender]] with the new genus if the specific epithet is an adjective modifying the genus name. Some biologists have argued for the combination of the genus name and specific epithet into a single unambiguous name, or for the use of uninomials (as used in nomenclature of ranks above species).<ref>{{cite journal |last=Michener |first=Charles D. |date=1964 |title=The possible use of uninominal nomenclature to increase the stability of names in biology |journal=Systematic Zoology |volume=13 |issue=4 |pages=182–190 |doi=10.2307/2411777 |jstor=2411777}}</ref><ref>{{cite journal |last1=Cantino |first1=P. D. |first2=H. D. |last2=Bryant |first3=K. |last3=de Queiroz |first4=M. J. |last4=Donoghue |first5=T. |last5=Eriksson |first6=D. M. |last6=Hillis |first7=M. S. Y. |last7=Lee |date=1999 |url=http://www.botany.wisc.edu/courses/botany_940/05PhyloCode/papers/Cantino%2699b.pdf |archive-url=https://ghostarchive.org/archive/20221009/http://www.botany.wisc.edu/courses/botany_940/05PhyloCode/papers/Cantino%2699b.pdf |archive-date=9 October 2022 |url-status=live |title=Species names in phylogenetic nomenclature |journal=Systematic Biology |volume=48 |issue=4 |pages=790–807 |doi=10.1080/106351599260012 |pmid=12066299 |doi-access=free}}</ref>
Because genus names are unique only within a nomenclature code, it is possible for homonyms (two or more species sharing the same genus name) to happen, and even the same binomial if they occur in different kingdoms. At least 1,258 instances of genus name duplication occur (mainly between zoology and botany).<ref name="hemi">{{cite web |title=HemiHomonym Database |url=http://herba.msu.ru/shipunov/os/homonyms/index.php |website=herba.msu.ru |access-date=17 November 2022 |archive-url=https://web.archive.org/web/20150512143402/http://herba.msu.ru/shipunov/os/homonyms/index.php |archive-date=12 May 2015}}</ref><ref name="HHDB">{{cite journal |last1=Shipunov |first1=Alexey |title=The problem of hemihomonyms and the on-line hemihomonyms database (HHDB) |journal=Bionomina |date=16 January 2013 |volume=4 |issue=1 |pages=65–72 |doi=10.11646/bionomina.4.1.3 |doi-access=free}}</ref>
==Relationship to classification and taxonomy==
Nomenclature (including binomial nomenclature) is not the same as classification, although the two are related. Classification is the ordering of items into groups based on similarities or differences; in [[Taxonomy (biology)|biological classification]], species are one of the kinds of item to be classified.<ref>{{cite book |last=Simpson |first=Michael G. |date=2006 |title=Plant Systematics |___location=London |publisher=Elsevier Academic Press |isbn=978-0-12-644460-5}}, p. 552</ref> In principle, the names given to species could be completely independent of their classification. This is not the case for binomial names, since the first part of a binomial is the name of the genus into which the species is placed. Above the rank of genus, binomial nomenclature and classification are partly independent; for example, a species retains its binomial name if it is moved from one family to another or from one order to another, unless it better fits a different genus in the same or different family, or it is split from its old genus and placed in a newly created genus. The independence is only partial since the names of families and other higher taxa are usually based on genera.
[[Taxonomy (biology)|Taxonomy]] includes both nomenclature and classification. Its first stages (sometimes called "[[alpha taxonomy]]") are concerned with finding, describing and naming species of living or [[fossil]] organisms.<ref name="Fortey">{{Citation |last=Fortey |first=Richard |author-link=Richard Fortey |date=2008 |title=Dry Store Room No. 1: The Secret Life of the Natural History Museum |___location=London |publisher=Harper Perennial |isbn=978-0-00-720989-7}}</ref> Binomial nomenclature is thus an important part of taxonomy as it is the system by which species are named. Taxonomists are also concerned with classification, including its principles, procedures and rules.<ref>{{cite book |last1=Davis |first1=Peter H. |author1-link=Peter Hadland Davis |last2=Heywood |first2=Vernon H. |author2-link=Vernon Heywood |date=1965 |title=Principles of Angiosperm Taxonomy |___location=Edinburgh |publisher=Oliver & Boyd |page=8}}</ref>
==Derivation of binomial names==
{{see also|List of Latin and Greek words commonly used in systematic names}}
A complete binomial name is always treated grammatically as if it were a phrase in the Latin language (hence the common use of the term "Latin name" for a binomial name). However, the two parts of a binomial name can each be derived from a number of sources, of which Latin is only one. These include:
* Latin, from any period, whether [[Latin|classical]], [[Medieval Latin|medieval]] or [[Neo-Latin|modern]]. Thus, both parts of the binomial name {{lang|la|Homo sapiens}} are Latin words, meaning "wise" ({{lang|la|sapiens}}) "human/man" ({{lang|la|Homo}}).
* [[Ancient Greek|Classical Greek]]. The genus ''[[Rhododendron]]'' was named by [[Carl Linnaeus|Linnaeus]] from the Greek word {{lang|grc|ῥοδόδενδρον}}, itself derived from ''rhodon'', "rose", and ''dendron'', "tree".<ref>{{OEtymD|rhododendron}}</ref><ref>{{LSJ|r(odo/dendron|ῥοδόδενδρον}}, {{LSJ|r(o/don|ῥόδον}}, {{LSJ|de/ndreon|δένδρον|ref}}.</ref> Greek words are often converted to a Latinized form. Thus coca (the plant from which cocaine is obtained) has the name ''[[Erythroxylum coca]]''. ''Erythroxylum'' is derived from the Greek words {{lang|grc-latn|erythros}}, red, and {{lang|grc-latn|xylon}}, wood.<ref>{{Harvnb|Hyam|Pankhurst|1995|p=182}}</ref> The Greek ending -{{lang|grc|ον}} (-on), when it is neuter, is often converted to the Latin neuter ending {{lang|la|-um}}.{{NoteTag|The ending "-on" may derive from the neuter Greek ending -{{lang|grc|ον}}, as in ''Rhodoxylon floridum'', or the masculine Greek ending -{{lang|grc|ων}}, as in ''Rhodochiton atrosanguineus''.}}
* Other languages. The second part of the name ''[[Erythroxylum coca]]'' is derived from {{lang|ay|kuka}}, the name of the plant in [[Aymara language|Aymara]] and [[Quechua languages|Quechua]].<ref>{{Ref Bertonio}}</ref><ref>{{Ref Laime}}</ref> Since many dinosaur fossils were found in Mongolia, their names often use [[Mongolian language|Mongolian]] words, e.g. ''[[Tarchia]]'' from {{lang|mn|tarkhi}}, meaning "brain", or ''[[Saichania]]'' meaning "beautiful one".
* Names of people (often naturalists or biologists). The name ''[[Magnolia campbellii]]'' commemorates two people: [[Pierre Magnol]], a French botanist, and [[Arthur Campbell (doctor)|Archibald Campbell]], a doctor in [[British India]].<ref>{{Harvnb|Hyam|Pankhurst|1995|p=303}}</ref>
* Names of places. The lone star tick, ''[[Amblyomma americanum]]'', is widespread in the United States.<ref>{{cite journal |first1=James E. |last1=Childs |first2=Christopher D. |last2=Paddock |title=The ascendancy of ''Amblyomma americanum'' as a vector of pathogens affecting humans in the United States |journal=[[Annual Review of Entomology]] |volume=48 |issue=1 |pages=307–337 |date=2003 |pmid=12414740 |doi=10.1146/annurev.ento.48.091801.112728 |url=https://zenodo.org/record/1234969 |access-date=13 December 2019 |archive-date=7 August 2020 |archive-url=https://web.archive.org/web/20200807030223/https://zenodo.org/record/1234969 |url-status=live}}</ref>
* Other sources. Some binomial names have been constructed from [[List of taxa named by anagrams|taxonomic anagram]]s or other re-orderings of existing names. Thus the name of the genus ''[[Muilla]]'' is derived by reversing the name ''[[Allium]]''.<ref>{{Harvnb|Hyam|Pankhurst|1995|p=329}}</ref> Names may also be derived from [[jokes]] or [[pun]]s. For example, [[Neal Evenhuis]] described a number of species of flies in a genus he named ''[[Pieza]]'', including ''[[Pieza pi]]'', ''[[Pieza rhea]]'', ''[[Pieza kake]]'', and ''[[Pieza deresistans]]''.<ref>{{cite journal|last1=Evenhuis|first1=Neal L.|title=''Pieza'', a new genus of microbombyliids from the New World (Diptera: Mythicomyiidae)|journal=Zootaxa|date=2002|volume=36|issue=1|pages=1–28|doi=10.11646/zootaxa.36.1.1}}</ref>
The first part of the name, which identifies the genus, must be a word that can be treated as a Latin [[Grammatical number|singular]] noun in the [[nominative case]]. It must be unique within the purview of each [[nomenclatural code]], but can be repeated between them. Thus ''[[Huia (plant)|Huia recurvata]]'' is an extinct species of plant, found as [[fossil]]s in [[Yunnan]], China,<ref>{{cite journal |last=Geng |first=Bao-Yin |date=1985 |title=''Huia recurvata'' – A New Plant from Lower Devonian of Southeastern Yunnan China |journal=Acta Botanica Sinica |volume=27 |issue=4 |pages=419–426 |url=http://en.cnki.com.cn/Article_en/CJFDTOTAL-ZWXB198504013.htm |access-date=7 February 2011 |language=zh, en |archive-date=7 July 2011 |archive-url=https://web.archive.org/web/20110707014652/http://en.cnki.com.cn/Article_en/CJFDTOTAL-ZWXB198504013.htm |url-status=live}}</ref> whereas ''[[Javan torrent frog|Huia masonii]]'' is a species of frog found in [[Java]], Indonesia.<ref>{{cite web |last1=Iskandar |first1=D. |last2=Mumpuni |first2=D. |date=2004 |title=IUCN Red List of Threatened Species: ''Huia masonii'' |work=IUCNRedList.org |publisher=[[International Union for Conservation of Nature]] |url=http://iucnredlist.org/details/58303/0 |access-date=19 June 2011 |archive-date=26 October 2012 |archive-url=https://web.archive.org/web/20121026102204/http://www.iucnredlist.org/details/58303/0 |url-status=live}}</ref>
<!--ADD BIT ABOUT FORMATION OF GENUS NAMES-->
The second part of the name, which identifies the species within the genus, is also treated grammatically as a Latin word. It can have one of a number of forms:
* The second part of a binomial may be an adjective. If so, the form of the adjective must agree with the genus name in [[grammatical gender|gender]]. Latin nouns can have three genders, masculine, feminine and neuter, and many Latin adjectives will have two or three different endings, depending upon the gender of the noun they refer to. The [[house sparrow]] has the binomial name {{lang|la|Passer domesticus}}. Here {{lang|la|domesticus}} ("domestic") simply means "associated with the house". The [[Nandina|sacred bamboo]] is {{lang|la|Nandina domestic<u>a</u>}}<ref>{{Harvnb|Hyam|Pankhurst|1995|p=334}}</ref> rather than {{lang|la|Nandina domestic<u>us</u>}}, since {{lang|la|Nandina}} is feminine whereas {{lang|la|Passer}} is masculine. The tropical fruit [[Lansium parasiticum|langsat]] is a product of the plant {{lang|la|Lansium parasitic<u>um</u>}}, since {{lang|la|Lansium}} is neuter. Some common endings for Latin adjectives in the three genders (masculine, feminine, neuter) are {{lang|la|-us}}, {{lang|la|-a}}, {{lang|la|-um}} (as in the previous example of {{lang|la|domesticus}}); {{lang|la|-is}}, {{lang|la|-is}}, {{lang|la|-e}} (e.g., {{lang|la|tristis}}, meaning "sad"); and {{lang|la|-or}} {{lang|la|-or}} {{lang|la|-us}} (e.g., {{lang|la|minor}}, meaning "smaller"). For further information, see [[Latin declension#Adjectives|Latin declension: Adjectives]].
* The second part of a binomial may be a noun in the nominative case. An example is the binomial name of the lion, which is {{lang|la|Panthera leo}}. Grammatically the noun is said to be in [[apposition]] to the genus name and the two nouns do not have to agree in gender; in this case, {{lang|la|Panthera}} is feminine and {{lang|la|leo}} is masculine.
[[File:Talauma hodgsonii.jpg|thumb|''[[Magnolia hodgsonii]]'']]
* The second part of a binomial may be a noun in the [[genitive case|genitive]] (possessive) case. The genitive case is constructed in a number of ways in Latin, depending on the [[Latin declension|declension]] of the noun. Common endings for masculine and neuter nouns are {{lang|la|-ii}} or {{lang|la|-i}} in the singular and {{lang|la|-orum}} in the plural, and for feminine nouns {{lang|la|-ae}} in the singular and {{lang|la|-arum}} in the plural. The noun may be part of a person's name, often the surname, as in the [[Tibetan antelope]] ({{lang|la|Pantholops hodgsonii}}), the shrub {{lang|la|[[Magnolia hodgsonii]]}}, or the [[olive-backed pipit]] ({{lang|la|Anthus hodgsoni}}). The meaning is "of the person named", so {{lang|la|Magnolia hodgsonii}} means "Hodgson's magnolia". The {{lang|la|-ii}} or {{lang|la|-i}} endings show that in each case Hodgson was a man (not the same one); had Hodgson been a woman, {{lang|la|hodgsonae}} would have been used. The person commemorated in the binomial name is not usually (if ever) the person who created the name; for example, {{lang|la|Anthus hodgsoni}} was named by [[Charles Wallace Richmond]], in honour of Hodgson. Rather than a person, the noun may be related to a place, as with {{lang|la|[[Latimeria chalumnae]]}}, meaning "of the [[Chalumna River]]". Another use of genitive nouns is in, for example, the name of the bacterium {{lang|la|[[Escherichia coli]]}}, where {{lang|la|coli}} means "of the [[colon (anatomy)|colon]]". This formation is common in parasites, as in {{lang|la|[[Xenos vesparum]]}}, where {{lang|la|vesparum}} means "of the wasps", since {{lang|la|Xenos vesparum}} is a parasite of wasps.
Whereas the first part of a binomial name must be unique within the purview of each nomenclatural code, the second part is quite commonly used in two or more genera (as is shown by examples of ''hodgsonii'' above), but cannot be used more than once within a single genus. The full binomial name must be unique within each code.
==Codes==
From the early 19th century<!--Strickland code was 1841--> onwards it became ever more apparent that a body of rules was necessary to govern scientific names. In the course of time these became [[nomenclature codes]]. The ''[[International Code of Zoological Nomenclature]]'' (''ICZN'') governs the naming of animals,<ref name=ICZN>{{Harvnb|International Commission on Zoological Nomenclature|1999}}</ref> the ''[[International Code of Nomenclature for algae, fungi, and plants]]'' (''ICNafp'') that of plants (including [[cyanobacteria]]), and the ''[[International Code of Nomenclature of Bacteria]]'' (''ICNB'') that of [[bacteria]] (including [[Archaea]]). [[Virus]] names are governed by the ''[[International Committee on Taxonomy of Viruses]]'' (''ICTV''), a taxonomic code, which determines taxa as well as names. These codes differ in certain ways, e.g.:
* "Binomial nomenclature" is the correct term for botany,<ref>[[#ICN2012|McNeill et al. 2012]], Article 23</ref> although it is also used by zoologists.<ref>{{cite book |last=Schmidt |first=Diane |date=2003 |title=Guide to reference and information sources in the zoological sciences |___location=Westport, Conn. |publisher=Libraries Unlimited |isbn=978-1-56308-977-0 |url-access=registration |url=https://archive.org/details/guidetoreference0000schm |page=[https://books.google.com/books?id=EqJrbvJU4uwC&pg=PA4 4]}}</ref> Since 1961,<ref name="ICZN1961_Chap2Article5">{{Cite book |title=International code of zoological nomenclature, adopted by the XV International Congress of Zoology / Code international de nomenclature zoologique, adopté par le XVe Congrès international de zoologie |last=International Commission on Zoological Nomenclature |publisher=The International Trust for Zoological Nomenclature |date=1961 |volume=1961 |edition=1 |___location=London |pages=11, 148 |language=fr, en |url=https://www.biodiversitylibrary.org/item/107561#page/33/mode/1up |doi=10.5962/bhl.title.50303 |access-date=29 March 2023 |archive-date=29 March 2023 |archive-url=https://web.archive.org/web/20230329170250/https://www.biodiversitylibrary.org/item/107561#page/33/mode/1up |url-status=live}} , [https://www.biodiversitylibrary.org/item/107561#page/172/mode/1up p148 Glossary] </ref> "binomi<u>n</u>al nomenclature" is the technically correct term in zoology.<ref name="ICZN1999_Chap2Article5">{{Harvnb|International Commission on Zoological Nomenclature|1999|loc=[https://code.iczn.org/chapter-2-the-number-of-words-in-the-scientific-names-of-animals/article-5-principle-of-binominal-nomenclature/?frame=1 Chapter 2, Article 5. Principle of Binominal Nomenclature]}} ({{Cite web |url=https://code.iczn.org/chapter-2-the-number-of-words-in-the-scientific-names-of-animals/article-5-principle-of-binominal-nomenclature/ |title=Article 5. Principle of Binominal Nomenclature | International Code of Zoological Nomenclature |access-date=29 March 2023 |archive-date=29 March 2023 |archive-url=https://web.archive.org/web/20230329164629/https://code.iczn.org/chapter-2-the-number-of-words-in-the-scientific-names-of-animals/article-5-principle-of-binominal-nomenclature/ |url-status=live}})</ref> A binomial name is also called a binomen (plural binomina) or {{not a typo|binominal|reason="Binomi'n'al", with an "n" before the "al", is the alternative name in the ICZN. Do not "correct" it.}} name.<ref name="ICZN1999_Glossary">{{Harvnb|International Commission on Zoological Nomenclature|1999|loc=[https://code.iczn.org/glossary/ Glossary – "binomen", "nomenclature, binominal"]}} ({{Cite web |url=https://code.iczn.org/glossary/ |title=Glossary | International Code of Zoological Nomenclature |access-date=29 March 2023 |archive-date=6 February 2023 |archive-url=https://web.archive.org/web/20230206072152/https://code.iczn.org/glossary/ |url-status=live}})</ref>
* Both codes consider the first part of the two-part name for a species to be the "generic name". In the zoological code (''ICZN''), the second part of the name is a "specific name". In the botanical code (''ICNafp''), it is a "specific epithet". Together, these two parts are referred to as a "species name" or "binomen" in the zoological code: or "species name", "binomial", or "binary combination" in the botanical code. "Species name" is the only term common to the two codes.
* The ''ICNafp'', the plant code, does not allow the two parts of a binomial name to be the same (such a name is called a [[tautonym]]), whereas the ''ICZN'', the animal code, does. Thus the American bison has the binomen ''Bison bison''; a name of this kind would not be allowed for a plant.
* The starting points, the time from which these codes are in effect (retroactively), vary from group to group. In [[botany]] the starting point will often be in 1753 (the year Carl Linnaeus first published ''[[Species Plantarum]]''). In [[zoology]] the starting point is 1758 (1 January 1758 is considered the date of the publication of Linnaeus's ''[[Systema Naturae]]'', 10th Edition, and also [[Carl Alexander Clerck|Clerck's]] ''Aranei Svecici''). [[Bacteriology]] started anew, with a starting point on 1 January 1980.<ref>{{cite web |last=Sneath |first=P. H. A. |date=2003 |publisher=International Union of Microbiological Societies |url=http://www.the-icsp.org/misc/Code_history.htm |access-date=20 June 2013 |work=The-ICSP.org |title=A short history of the Bacteriological Code |archive-date=24 May 2012 |archive-url=https://web.archive.org/web/20120524070542/http://www.the-icsp.org/misc/Code_history.htm}}</ref>
{| class="wikitable"
|+ Summary of terminology for the names of species in the ICZN and ICNafp
! Code !! Full name !! First part !! Second part
|-
| ICZN || species name, binomen, binominal name || generic name, genus name || specific name
|-
| ICNafp || species name, binary combination, binomial (name) || generic name || specific epithet
|}
Unifying the different codes into a single code, the "''BioCode''", has been suggested,<ref>{{Cite web |title=Draft Biocode |url=https://www.bgbm.org/IAPT/biocode/default.htm |access-date=2025-02-01 |website=www.bgbm.org}}</ref> although implementation is not in sight. (There is also a published code for a different system of biotic nomenclature, which does not use ranks above species, but instead names [[clade]]s. This is called ''[[PhyloCode]]''.)
===Differences in handling personal names===
As noted above, there are some differences between the codes in how binomials can be formed; for example the ''ICZN'' allows both parts to be the same, while the ''ICNafp'' does not. Another difference is in how personal names are used in forming specific names or epithets. The ''ICNafp'' sets out precise rules by which a personal name is to be converted to a specific epithet. In particular, names ending in a consonant (but not "er") are treated as first being converted into Latin by adding "-ius" (for a man) or "-ia" (for a woman), and then being made genitive (i.e. meaning "of that person or persons"). This produces specific epithets like ''lecardii'' for Lecard (male), ''wilsoniae'' for Wilson (female), and ''brauniarum'' for the Braun sisters.<ref>[[#ICN2012|McNeill et al. 2012]], Recommendation 60C</ref> By contrast, the ''ICZN'' does not require the intermediate creation of a Latin form of a personal name, allowing the genitive ending to be added directly to the personal name.<ref>{{Harvnb|International Commission on Zoological Nomenclature|1999}}, Chap. 7, Article 3.1.2</ref> This explains the difference between the names of the plant ''Magnolia hodgsonii'' and the bird ''Anthus hodgsoni''. Furthermore, the ''ICNafp'' requires names not published in the form required by the code to be corrected to conform to it,<ref>[[#ICN2012|McNeill et al. 2012]], Article 60.12</ref> whereas the ''ICZN'' is more protective of the form used by the original author.<ref>{{Harvnb|International Commission on Zoological Nomenclature|1999}}, Chap. 7, Article 32.3</ref>
== Writing binomial names ==
By tradition, the binomial names of species are usually typeset in italics; for example, ''[[Homo sapiens]]''.<ref name="howto">{{cite journal |title=How to Write Scientific Names of Organisms |journal=Competition Science Vision |url=http://www.journal.au.edu/au_techno/2001/oct2001/howto.pdf |access-date=20 June 2011 |archive-date=4 July 2011 |archive-url=https://web.archive.org/web/20110704203742/http://www.journal.au.edu/au_techno/2001/oct2001/howto.pdf |url-status=live}}</ref> Generally, the binomial should be printed in a [[font|font style]] different from that used in the normal text; for example, "''Several more ''Homo sapiens'' fossils were discovered''." When handwritten, a binomial name should be underlined; for example, <u>Homo</u> <u>sapiens</u>.<ref name="tan">{{cite web |url=http://www.cdtl.nus.edu.sg/success/sl43.htm |title=Understanding and Learning Scientific Names of Species |last1=Tan |first1=Hugh T.W. |last2=Tan |first2=Kai-xin |publisher=Successful Learning, Center for Development of Teaching and Learning, National University of Singapore |work=CDTL.NUS.edu.sg |access-date=20 June 2011 |archive-date=21 July 2011 |archive-url=https://web.archive.org/web/20110721013443/http://www.cdtl.nus.edu.sg/success/sl43.htm |url-status=live}}</ref>
The first part of the binomial, the genus name, is always written with an initial capital letter. Older sources, particularly botanical works published before the 1950s, used a different convention: if the second part of the name was derived from a proper noun, e.g., the name of a person or place, a capital letter was used. Thus, the modern form ''Berberis darwinii'' was written as ''Berberis Darwinii''. A capital was also used when the name is formed by two nouns in apposition, e.g., ''Panthera Leo'' or ''Centaurea Cyanus''.{{sfn|Johnson|Smith|1972|p=23}}{{NoteTag|The modern notation was resisted by some, partly because writing names like ''Centaurea cyanus'' can suggest that ''cyanus'' is an adjective which should agree with ''Centaurea'', i.e. that the name should be ''Centaurea cyana'', whereas ''Cyanus'' is derived from the Greek name for the cornflower.<ref>{{cite book |last=Gilbert-Carter |first=H. |date=1955 |title=Glossary of the British Flora |edition=2nd |publisher=Cambridge University Press |oclc=559413416 |page=xix}}</ref>}} In current usage, the second part is never written with an initial capital.<ref>{{cite book |last=Silyn-Roberts |first=Heather |date=2000 |title=Writing for Science and Engineering: Papers, Presentations and Reports |___location=Oxford; Boston |publisher=Butterworth-Heinemann |isbn=978-0-7506-4636-9 |page=[https://books.google.com/books?id=hVUU7Gq8QskC&pg=PA198 198]}}</ref><ref>[[#ICN2012|McNeill et al. 2012]], Recommendation 60F</ref>
When used with a common name, the scientific name often follows in parentheses, although this varies with publication.<ref name="parenth">{{cite book |url=http://www.gse.mq.edu.au/resources/guide/format.htm |title=Writing Guide: Language, Words and Format |___location=Sydney, NSW |publisher=Macquarie University |archive-date=29 June 2011 |archive-url=https://web.archive.org/web/20110629140234/http://www.gse.mq.edu.au/resources/guide/format.htm}}</ref> For example, "The house sparrow (''Passer domesticus'') is decreasing in Europe."
The binomial name should generally be written in full. The exception to this is when several species from the same genus are being listed or discussed in the same paper or report, or the same species is mentioned repeatedly; in which case the genus is written in full when it is first used, but may then be abbreviated to an initial (and a period/full stop).<ref name="merriamwebster">{{cite book |title=Merriam-Webster's Collegiate Dictionary |publisher=Merriam-Webster |chapter=Linnaean Nomenclature of Plants, Animals, & Bacteria |date=2003 |page=[https://archive.org/details/merriamwebstersc00merr_6/page/22 22a – 23a] |isbn=978-0-87779-809-5 |chapter-url=https://books.google.com/books?id=TAnheeIPcAEC&pg=PP28 |url-access=registration |url=https://archive.org/details/merriamwebstersc00merr_6/page/22}}</ref> For example, a list of members of the genus ''Canis'' might be written as "''Canis lupus'', ''C. aureus'', ''C. simensis''". In rare cases, this abbreviated form has spread to more general use; for example, the bacterium ''[[Escherichia coli]]'' is often referred to as just ''E. coli'', and ''[[Tyrannosaurus|Tyrannosaurus rex]]'' is perhaps even better known simply as ''T. rex'', these two both often appearing in this form in popular writing even where the full genus name has not already been given.
The abbreviation "sp." is used when the actual specific name cannot or need not be specified. The abbreviation "spp." (standing for ''species pluralis'', Latin for "multiple species") indicates "several species". These abbreviations are not italicised (or underlined).<ref name="Springer: PKR and VD Nair">{{cite book |last1=Nair |first1=P. K. Ramachandran |author-link1=P. K. Ramachandran Nair |last2=Nair |first2=Vimala D. |date=2014 |title=Scientific Writing and Communication in Agriculture and Natural Resources |url=https://books.google.com/books?id=Uxm4BAAAQBAJ&pg=PA39 |publisher=[[Springer Science+Business Media|Springer International Publishing]] |page=39 |doi=10.1007/978-3-319-03101-9 |isbn=978-3-319-03101-9 |s2cid=11811479 |lccn=2013953625 |oclc=881314963 |access-date=20 March 2023 |archive-date=28 March 2023 |archive-url=https://web.archive.org/web/20230328005811/https://books.google.com/books?id=Uxm4BAAAQBAJ&pg=PA39 |url-status=live}}</ref><ref name="jenks">{{cite web |url=http://www.hort.purdue.edu/hort/courses/hort217/Nomenclature/description.htm |archive-url=https://archive.today/20121211140110/http://www.hort.purdue.edu/hort/courses/hort217/Nomenclature/description.htm |archive-date=11 December 2012 |title=Plant Nomenclature |first=Matthew A. |last=Jenks |publisher=Department of Horticulture and Landscape Architecture, Purdue University |work=Hort.Purdue.edu |access-date=20 June 2011}}</ref> For example: "''Canis'' sp." means "an unspecified species of the genus ''[[Canis]]''", while "''Canis'' spp." means "two or more species of the genus ''Canis''". (These abbreviations should not be confused with the abbreviations "ssp." (zoology) or "subsp." (botany), plurals "sspp." or "subspp.", referring to one or more [[subspecies]]. See [[trinomen]] (zoology) and [[infraspecific name]].)
The abbreviation "[[cf.]]" (i.e., ''confer'' in Latin) is used to compare individuals/taxa with known/described species. Conventions for use of the "cf." qualifier vary.<ref name="clowes">{{cite web |url=http://www.peripatus.gen.nz/biology/priTaxonomy.html |title=Taxonomy – A Primer |first=Chris |last=Clowes |work=Peripatus.Gen.nz |access-date=20 June 2011 |archive-date=7 August 2011 |archive-url=https://web.archive.org/web/20110807091803/https://www.peripatus.gen.nz/biology/priTaxonomy.html}}</ref> In paleontology, it is typically used when the identification is not confirmed.<ref>{{cite journal |last=Bengtson |first=P. |date=1988 |title=Open nomenclature |journal=Palaeontology |volume=31 |issue=1 |pages=223–227 |url=http://www.palass-pubs.org/palaeontology/pdf/Vol31/Pages%20223-227.pdf |archive-url=https://web.archive.org/web/20141006071437/http://www.palass-pubs.org/palaeontology/pdf/Vol31/Pages%20223-227.pdf |archive-date=6 October 2014 |url-status=usurped |access-date=22 August 2014}}</ref> For example, "''Corvus'' cf. ''nasicus''" was used to indicate "a fossil bird similar to the [[Cuban crow]] but not certainly identified as this species".<ref>{{cite journal |last=Orihuela |first=J. |date=2013 |url=http://birdscaribbean.org/jco/index.php/jco/article/view/32 |title=Fossil Cuban crow ''Corvus'' cf. ''nasicus'' from a late Quaternary cave deposit in northern Matanzas, Cuba |journal=Journal of Caribbean Ornithology |volume=26 |pages=12–16 |access-date=22 August 2014 |archive-date=27 January 2018 |archive-url=https://web.archive.org/web/20180127004555/http://birdscaribbean.org/jco/index.php/jco/article/view/32 |url-status=live}}</ref> In molecular systematics papers, "cf." may be used to indicate one or more undescribed species assumed to be related to a described species. For example, in a paper describing the phylogeny of small benthic freshwater fish called darters, five undescribed putative species (Ozark, Sheltowee, Wildcat, Ihiyo, and Mamequit darters), notable for brightly colored nuptial males with distinctive color patterns,<ref>{{cite book |last1=Page |first1=L. M. |last2=Burr |first2=B. M. |date=1991 |title=Peterson field guide to freshwater fishes: North America north of Mexico |url=https://archive.org/details/fieldguidetofres00lawr |url-access=registration |publisher=Houghton Mifflin Harcourt |isbn=978-0-547-24206-4 |at=plate 52}}</ref> were referred to as "''Etheostoma'' cf. ''spectabile''" because they had been viewed as related to, but distinct from, ''Etheostoma spectabile'' (orangethroat darter).<ref>{{cite journal |last1=Near |first1=T. J. |last2=Bossu |first2=C. M. |last3=Bradburd |first3=G. S. |last4=Carlson |first4=R. L. |last5=Harrington |first5=R. C. |last6=Hollingsworth |first6=P. R. |last7=Keck |first7=B. P. |last8=Etnier |first8=D. A. |date=2011 |title=Phylogeny and temporal diversification of darters (Percidae: Etheostomatinae) |journal=Systematic Biology |volume=60 |issue=5 |pages=565–595 |doi=10.1093/sysbio/syr052 |doi-access=free |pmid=21775340}}</ref> This view was supported to varying degrees by DNA analysis. The somewhat informal use of taxa names with qualifying abbreviations is referred to as [[open nomenclature]] and it is not subject to strict usage codes.
In some contexts, the dagger symbol ("†") may be used before or after the binomial name to indicate that the species is extinct.
{{anchor|Authority}}
=== Authority ===
{{main|Author citation (zoology)|Author citation (botany)}}
In scholarly texts, at least the first or main use of the binomial name is usually followed by the "authority" – a way of designating the scientist(s) who first published the name. The authority is written in slightly different ways in zoology and botany. For names governed by the ''ICZN'' the surname is usually written in full together with the date (normally only the year) of publication. One example of author citation of scientific name is: "[[Amabela|''Amabela'' Möschler, 1880]]."{{NoteTag|Here Amabela is the name of the [[genus]]. It is written in italic form. Followed by the last name of the scientist who discovered it (Heinrich Benno '''Möschler'''), a comma, and the year when it was published.}} The ''ICZN'' recommends that the "original author and date of a name should be cited at least once in each work dealing with the taxon denoted by that name."{{sfn|International Commission on Zoological Nomenclature |1999|loc=Recommendation 51a}} For names governed by the ''ICNafp'' the name is generally reduced to a standard abbreviation and the date omitted. The [[International Plant Names Index]] maintains an approved list of botanical author abbreviations. Historically, abbreviations were used in zoology too.
When the original name is changed, e.g., the species is moved to a different genus, both codes use parentheses around the original authority; the ''ICNafp'' also requires the person who made the change to be given. In the ''ICNafp'', the original name is then called the [[basionym]]. Some examples:
* (Plant) ''[[Amaranthus retroflexus]]'' L. – "L." is the standard abbreviation for "Linnaeus"; the absence of parentheses shows that this is his original name.
* (Plant) ''[[Hyacinthoides italica]]'' (L.) Rothm. – Linnaeus first named the Italian bluebell ''Scilla italica''; that is the basionym. [[Werner Hugo Paul Rothmaler|Rothmaler]] later transferred it to the genus ''Hyacinthoides''.
* (Animal) ''[[Passer domesticus]]'' (Linnaeus, 1758) – the original name given by Linnaeus was ''Fringilla domestica''; unlike the ''ICNafp'', the ''ICZN'' does not require the name of the person who changed the genus ([[Mathurin Jacques Brisson]]<ref>{{Cite book |last=Summers-Smith |first=J. Denis |title=The Sparrows |publisher=T. & A. D. Poyser |date=1988 |___location=Calton, Staffordshire, England |isbn=978-0-85661-048-6 |others=illustrated by Robert Gillmor |url-access=registration |url=https://archive.org/details/sparrowsstudyofg0000summ |pages=114–115}}</ref>) to be given.
==Other ranks==
{{main|Biological nomenclature|Trinomial nomenclature|Infraspecific name (botany)}}
Binomial nomenclature, as described here, is a system for naming species. Implicitly, it includes a system for naming genera, since the first part of the name of the species is a genus name. In a classification system based on ranks, there are also ways of naming ranks above the level of genus and below the level of species. Ranks above genus (e.g., family, order, class) receive one-part names, which are conventionally not written in italics. Thus, the house sparrow, ''[[House sparrow|Passer domesticus]]'', belongs to the family [[Passeridae]]. [[Family (biology)|Family]] names are normally based on genus names, such as in zoology,<ref>{{Cite web |title=The Code Online {{!}} International Commission on Zoological Nomenclature |url=https://code.iczn.org/chapter-4-criteria-of-availability/article-11-requirements/?frame=1#art-11-7 |access-date=2025-02-01 |website=www.iczn.org |at=11.7. Family-group names}}</ref> although the endings used differ between zoology and botany.
Ranks below species receive three-part names, conventionally written in italics like the names of species. There are significant differences between the ''ICZN'' and the ''ICNafp''. In zoology, the only formal rank below species is subspecies and the name is written simply as three parts (a trinomen). Thus, one of the subspecies of the [[olive-backed pipit]] is ''Anthus hodgsoni berezowskii''. Informally, in some circumstances, a [[Form (zoology)|form]] may be appended. For example ''[[Harmonia axyridis]]'' f. ''spectabilis'' is the harlequin ladybird in its black or melanic forms having four large orange or red spots. In botany, there are many ranks below species and although the name itself is written in three parts, a "connecting term" (not part of the name) is needed to show the rank. Thus, the American black elder is ''Sambucus nigra'' subsp. ''canadensis''; the white-flowered form of the ivy-leaved cyclamen is ''[[Cyclamen hederifolium]]'' f. ''albiflorum''.<ref>{{Cite web |title=Article 26 |url=https://www.iapt-taxon.org/nomen/pages/main/art_26.html?zoom_highlight=below+species |access-date=2025-02-01 |website=www.iapt-taxon.org}}</ref>
==See also==
* [[Glossary of scientific naming]]
* [[Botanical name]]
* [[Hybrid name (botany)]]
* [[List of botanists by author abbreviation]]
* [[List of Latin and Greek words commonly used in systematic names]]
* [[List of organisms named after famous people]]
* [[List of zoologists by author abbreviation]]
* [[Scientific terminology]]
* [[Species description]]
* [[Undescribed taxon]]
== Notes ==
{{NoteFoot}}
==References==
{{Reflist}}
==Bibliography==
* {{Cite book |last1=Hyam |first1=R. |last2=Pankhurst |first2=R. J. |date=1995 |title=Plants and their names: A concise dictionary |___location=Oxford |publisher=Oxford University Press |isbn=978-0-19-866189-4}}
* {{cite book |last1=Johnson |first1=A.T. |last2=Smith |first2=H. A. |date=1972 |title=Plant Names Simplified: Their Pronunciation Derivation & Meaning |publication-place=Buckenhill, Herefordshire |publisher=Landsmans Bookshop |isbn=978-0-900513-04-6}}
* {{cite book |last=International Commission on Zoological Nomenclature |date=1999 |title=International Code of Zoological Nomenclature online |edition=4th |publisher=The International Trust for Zoological Nomenclature |isbn=978-0-85301-006-7 |url=http://www.nhm.ac.uk/hosted-sites/iczn/code/ |access-date=20 June 2011}}
* {{cite book |last1=McNeill |first1=J. |last2=Barrie |first2=F. R. |last3=Buck |first3=W. R. |last4=Demoulin |first4=V. |last5=Greuter |first5=W. |last6=Hawksworth |first6=D. L. |last7=Herendeen |first7=P. S. |last8=Knapp |first8=S. |last9=Marhold |first9=K. |last10=Prado |first10=J. |last11=Prud'homme Van Reine |first11=W. F. |last12=Smith |first12=G. F. |last13=Wiersema |first13=J. H. |last14=Turland |first14=N. J. |date=2012 |series=Regnum Vegetabile 154 |title=International Code of Nomenclature for algae, fungi, and plants (Melbourne Code) adopted by the Eighteenth International Botanical Congress Melbourne, Australia, July 2011 |___location=Königstein, Germany |publisher=Koeltz Scientific Books |isbn=978-3-87429-425-6 |ref=ICN2012 |url=http://www.iapt-taxon.org/nomen/main.php?page=title |url-status=deviated |archive-date=7 May 2017 |archive-url=https://web.archive.org/web/20170507070323/http://www.iapt-taxon.org/nomen/main.php?page=title}}
==Further reading==
* {{cite book |date=2007 |editor-last=Crinan |editor-first=Alexander |title=Plant Names: A Guide for Horticulturists, Nurserymen, Gardeners and Students |publisher=[[Hortax|Horticultural Taxonomy Group]], Royal Botanic Garden Edinburgh |url=http://www.hortax.org.uk/uploads/4/1/3/5/4135326/hortax_plantnames.pdf |access-date=4 June 2013 |archive-url=https://web.archive.org/web/20130927205640/http://www.hortax.org.uk/uploads/4/1/3/5/4135326/hortax_plantnames.pdf |archive-date=27 September 2013}}
==External links==
{{Commons category|Biological nomenclature}}
* {{Wikispecies-inline|List of valid homonyms}}
* [http://www.curioustaxonomy.net/index.html Curiosities of Biological Nomenclature]
* [https://www.ncbi.nlm.nih.gov/taxonomy NCBI Taxonomy Database]
{{Carl Linnaeus}}
{{Authority control}}
{{Interwiki extra|qid=Q10753560}}
[[Category:Biological nomenclature| ]]
[[Category:Neo-Latin terminology]]
| |||