Author citation (botany)

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In botanical nomenclature, author citation is the way of citing the person or group of people who validly published a botanical name, i.e. who first published the name while fulfilling the formal requirements as specified by the International Code of Nomenclature for algae, fungi, and plants (ICN). [1] In cases where a species is no longer in its original generic placement (i.e. a new combination of genus and specific epithet), both the authority for the original genus placement and that for the new combination are given (the former in parentheses).


In botany, it is customary (though not obligatory) to abbreviate author names according to a recognised list of standard abbreviations.

There are differences between the botanical code and the normal practice in zoology. In zoology, the publication year is given following the author names and the authorship of a new combination is normally omitted. A small number of more specialized practices also vary between the recommendations of the botanical and zoological codes.


In biological works, particularly those dealing with taxonomy and nomenclature but also in ecological surveys, it has long been the custom that full citations to the place where a scientific name was published are omitted, but a short-hand is used to cite the author of the name, at least the first time this is mentioned. The author name is frequently not sufficient information, but can help to resolve some difficulties. Problems include:

Rules and recommendations for author citations in botany are covered by Articles 46–50 of the International Code of Nomenclature (ICN). [1] As stated in Article 46 of the botanical Code, in botany it is normal to cite only the author of the taxon name as indicated in the published work, even though this may differ from the stated authorship of the publication itself.

Basic citation

The simplest form of author citation in botany applies when the name is cited in its original rank and its original genus placement (for binomial names and below), where the original author (or authors) are the only name/s cited, and no parentheses are included.

The Latin term "et" or the ampersand symbol "&" can be used when two authors jointly publish a name. [1] Recommendation 46C.1

In many cases the author citation will consist of two parts, the first in parentheses, e.g.:

This form of author citation indicates that the epithet was originally published in another genus (in this case as Cistus coridifolius) by the first author, Dominique Villars (indicated by the enclosing parentheses), but moved to the present genus Helianthemum by the second (revising) author (António Xavier Pereira Coutinho). Alternatively, the revising author changed the rank of the taxon, for example raising it from subspecies to species (or vice versa), from subgenus to Section, etc. [1] Article 49 (Again, the latter is in contrast to the situation in zoology, where no authorship change is recognized within family-group, genus-group, and species-group names, thus a change from subspecies to species, or subgenus to genus, is not associated with any change in cited authorship).


When citing a botanical name including its author, the author's name is often abbreviated. To encourage consistency, the International Code of Nomenclature for algae, fungi, and plants ICN recommends [1] Recommendation 46A, Note 1 the use of Brummitt & Powell's Authors of Plant Names (1992), where each author of a botanical name has been assigned a unique abbreviation. [2] These standard abbreviations can be found at the International Plant Names Index. [3]

For example, in:

the abbreviation "L." refers to the famous botanist Carl Linnaeus who described this genus on p. 492 of his Species Plantarum in 1753.

the abbreviation "Cham." refers to the botanist Adelbert von Chamisso and "Schldl." to the botanist Diederich Franz Leonhard von Schlechtendal; these authors jointly described this species (and placed it in the genus Rubus ) in 1827.

Usage of the term "ex"

When "ex" is a component of the author citation, it denotes the fact that an initial description did not satisfy the rules for valid publication, but that the same name was subsequently validly published by a second author or authors (or by the same author in a subsequent publication). [1] Article 46.4 However, if the subsequent author makes clear that the description was due to the earlier author (and that the earlier author accepted the name), then no "ex" is used, and the earlier author is listed alone. For example:

indicates that Josef Schultes validly published this name (in 1824 in this instance), but his description was based on an earlier description by Franz Sieber. (Note that in botany, the author of the earlier name precedes the later, valid one; in zoology, this sequence (where present) is reversed.)


The following forms of citation are all equally correct:

As indicated above, either the original or the revising author may involve multiple words, as per the following examples from the same genus:

Usage of the ancillary term "in"

The ancillary term "in" is sometimes employed to indicate that the authorship of the published work is different from that of the name itself, for example:

Article 46.2 Note 1 of the Botanical Code indicates that in such cases, the portion commencing "in" is in fact a bibliographic citation and should not be used without the place of publication being included, thus the preferred form of the name+author alone in this example would be Verrucaria aethiobola Wahlenb., not Verrucaria aethiobola Wahlenb. in Acharius. (This is in contrast to the situation in zoology, where either form is permissible, and in addition a date would normally be appended.)

Authorship of subsidiary ranks

According to the botanical Code it is only necessary to cite the author for the lowest rank of the taxon in question, i.e. for the example subspecies given above (Helianthemum apenninum subsp. rothmaleri) it is not necessary (or even recommended) to cite the authority of the species ("Mill.") as well as that of the subspecies,[ citation needed ] though this is found in some sources. The only exception to this rule is where the nominate variety or subspecies of a species is cited, which automatically will inherit the same authorship of its parent taxon, [1] Article 26.1 thus:

Emending authors

As described in Article 47 of the botanical code, on occasion either the diagnostic characters or the circumscription of a taxon may be altered ("emended") sufficiently that the attribution of the name to the original taxonomic concept as named is insufficient. The original authorship attribution is not altered in these cases, but a taxonomic statement can be appended to the original authorship using the abbreviation "emend." (for emendavit), as per these examples given in the Code:

(In the second example, "excl. var.", abbr. for exclusis varietatibus, indicates that this taxonomic concept excludes varieties which other workers have subsequently included).

Other indications

Other indications which may be encountered appended to scientific name authorship include indications of nomenclatural or taxonomic status (e.g. "nom. illeg.", "sensu Smith", etc.), prior taxonomic status for taxa transferred between hybrid and non-hybrid status ("(pro sp.)" and "(pro hybr.)", see Article 50 of the botanical Code), and more. Technically these do not form part of the author citation but represent supplementary text, however they are sometimes included in "authority" fields in less well constructed taxonomic databases. Some specific examples given in Recommendations 50A–F of the botanical Code include:

for a taxon name published without an acceptable description or diagnosis

for a homonym—indicating in this instance that Carl Peter Thunberg's "Lindera" is not the same taxon as that named previously by Michel Adanson, the correspondence of the two names being coincidental

as above, but two prior (and quite possibly unrelated) homonyms noted, the first by Ludwig Reichenbach, the second by Ferdinand von Mueller

for a taxon name rejected (normally in favour of a later usage) and placed on the list of rejected names forming an appendix to the botanical Code (the alternative name conserved over the rejected name would be cited as "nom. cons.")

this is the preferred syntax for a name that has been misapplied by a subsequent author or authors ("auct." or "auctt.") such that it actually represents a different taxon from the one to which Vahl's name correctly applies

indicating that the epithet as originally published was spelled solomonensis, but the spelling here is in an altered form, presumably for Code compliance or some other legitimate reason.

See also

Specific to botany
More general

Related Research Articles

A genus is a taxonomic rank used in the biological classification of living and fossil organisms, as well as viruses, in biology. In the hierarchy of biological classification, genus comes above species and below family. In binomial nomenclature, the genus name forms the first part of the binomial species name for each species within the genus.

Binomial nomenclature System of identifying species of organisms using a two-part name

Binomial nomenclature, also called binominal nomenclature or 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 grammatical forms, although they can be based on words from other languages. Such a name is called a binomial name, a binomen, binominal name or a scientific name; more informally it is also called a Latin name.

Taxon Group of one or more populations of an organism or organisms which have distinguishing characteristics in common

In biology, a taxon is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular name and given a particular ranking, especially if and when it is accepted or becomes established. It is very common, however, for taxonomists to remain at odds over what belongs to a taxon and the criteria used for inclusion. If a taxon is given a formal scientific name, its use is then governed by one of the nomenclature codes specifying which scientific name is correct for a particular grouping.

<i>International Code of Nomenclature for algae, fungi, and plants</i> Code of scientific nomenclature

The International Code of Nomenclature for algae, fungi, and plants (ICN) is the set of rules and recommendations dealing with the formal botanical names that are given to plants, fungi and a few other groups of organisms, all those "traditionally treated as algae, fungi, or plants". It was formerly called the International Code of Botanical Nomenclature (ICBN); the name was changed at the International Botanical Congress in Melbourne in July 2011 as part of the Melbourne Code which replaced the Vienna Code of 2005.

Type species

In zoological nomenclature, a type species is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specimen(s). A similar concept is used for suprageneric groups and called a type genus.

Type (biology) Specimen(s) to which a scientific name is formally attached

In biology, a type is a particular specimen of an organism to which the scientific name of that organism is formally attached. In other words, a type is an example that serves to anchor or centralize the defining features of that particular taxon. In older usage, a type was a taxon rather than a specimen.

Botanical name Scientific name for a plant, alga or fungus

A botanical name is a formal scientific name conforming to the International Code of Nomenclature for algae, fungi, and plants (ICN) and, if it concerns a plant cultigen, the additional cultivar or Group epithets must conform to the International Code of Nomenclature for Cultivated Plants (ICNCP). The code of nomenclature covers "all organisms traditionally treated as algae, fungi, or plants, whether fossil or non-fossil, including blue-green algae (Cyanobacteria), chytrids, oomycetes, slime moulds and photosynthetic protists with their taxonomically related non-photosynthetic groups ."

In botany, the correct name according to the International Code of Nomenclature for algae, fungi, and plants (ICN) is the one and only botanical name that is to be used for a particular taxon, when that taxon has a particular circumscription, position and rank. Determining whether a name is correct is a complex procedure. The name must be validly published, a process which is defined in no less than 16 Articles of the ICN. It must also be "legitimate", which imposes some further requirements. If there are two or more legitimate names for the same taxon, then the correct name is the one which has priority, i.e. it was published earliest, although names may be conserved if they have been very widely used. Validly published names other than the correct name are called synonyms. Since taxonomists may disagree as to the circumscription, position or rank of a taxon, there can be more than one correct name for a particular plant. These may also be called synonyms.

In botany, an infraspecific name is the scientific name for any taxon below the rank of species, i.e. an infraspecific taxon. The scientific names of botanical taxa are regulated by the International Code of Nomenclature for algae, fungi, and plants (ICN). This specifies a 'three part name' for infraspecific taxa, plus a 'connecting term' to indicate the rank of the name. An example of such a name is Astrophytum myriostigma subvar. glabrum, the name of a subvariety of the species Astrophytum myriostigma.

In zoological nomenclature, author citation refers to listing the person who first makes a scientific name of a taxon available. This is done in a scientific publication while fulfilling the formal requirements under the International Code of Zoological Nomenclature, hereinafter termed "the Code". According to the Code, "the name of the author does not form part of the name of a taxon and its citation is optional, although customary and often advisable", however Recommendation 51A suggests: "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. This is especially important in distinguishing between homonyms and in identifying species-group names which are not in their original combinations". For the purpose of information retrieval, the author citation and year appended to the scientific name, e.g. genus-species-author-year, genus-author-year, family-author-year, etc., is often considered a "de facto" unique identifier, although for a number of reasons discussed below, this usage may often be imperfect.

In biology, a homonym is a name for a taxon that is identical in spelling to another such name, that belongs to a different taxon.

A conserved name or nomen conservandum is a scientific name that has specific nomenclatural protection. That is, the name is retained, even though it violates one or more rules which would otherwise prevent it from being legitimate. Nomen conservandum is a Latin term, meaning "a name to be conserved". The terms are often used interchangeably, such as by the International Code of Nomenclature for Algae, Fungi, and Plants (ICN), while the International Code of Zoological Nomenclature favours the term "conserved name".

In botanical nomenclature, autonyms are automatically created names, as regulated by the International Code of Nomenclature for algae, fungi, and plants that are created for certain subdivisions of genera and species, those that include the type of the genus or species. An autonym might not be mentioned in the publication that creates it as a side-effect. Autonyms "repeat unaltered" the genus name or species epithet of the taxon being subdivided, and no other name for that same subdivision is validly published. For example, Rubus subgenus Eubatus is not validly published, and the subgenus is known as Rubus subgen. Rubus.

The Botanical and Zoological Codes of nomenclature treat the concept of synonymy differently. In botanical nomenclature, a synonym is a scientific name that applies to a taxon that (now) goes by a different scientific name. For example, Linnaeus was the first to give a scientific name to the Norway spruce, which he called Pinus abies. This name is no longer in use: it is now a synonym of the current scientific name, Picea abies. In zoology, moving a species from one genus to another results in a different binomen, but the name is considered an alternative combination, rather than a synonym. The concept of synonymy in zoology is reserved for two names at the same rank that refer to a taxon at that rank - for example, the name Papilio prorsaLinnaeus, 1758 is a junior synonym of Papilio levanaLinnaeus, 1758, being names for different seasonal forms of the species now referred to as Araschnia levana(Linnaeus, 1758), the map butterfly. However, Araschnia levana is not a synonym of Papilio levana in the taxonomic sense employed by the Zoological code.

Undescribed taxon A taxon that has been discovered but not yet formally described and named

In taxonomy, an undescribed taxon is a taxon that has been discovered, but not yet formally described and named. The various Nomenclature Codes specify the requirements for a new taxon to be validly described and named. Until such a description has been published, the taxon has no formal or official name, although a temporary, informal name is often used. A published scientific name may not fulfil the requirements of the Codes for various reasons. For example, if the taxon was not adequately described, its name is called a nomen nudum. It is possible for a taxon to be "undescribed" for an extensive period of time, even if unofficial descriptions are published.

Principle of Priority

Priority is a fundamental principle of modern botanical nomenclature and zoological nomenclature. Essentially, it is the principle of recognising the first valid application of a name to a plant or animal. There are two aspects to this:

  1. The first formal scientific name given to a plant or animal taxon shall be the name that is to be used, called the valid name in zoology and correct name in botany.
  2. Once a name has been used, no subsequent publication of that name for another taxon shall be valid (zoology) or validly published (botany).
Taxonomic rank Level in a taxonomic hierarchy

In biological classification, taxonomic rank is the relative level of a group of organisms in a taxonomic hierarchy. Examples of taxonomic ranks are species, genus, family, order, class, phylum, kingdom, domain, etc.

In biodiversity informatics, a chresonym is the cited use of a taxon name, usually a species name, within a publication. The term is derived from the Greek χρῆσις chresis meaning "a use" and refers to published usage of a name.

Nomen illegitimum is a technical term, used mainly in botany. It is usually abbreviated as nom. illeg. Although the International Code of Nomenclature for algae, fungi, and plants uses Latin terms for other kinds of name, the glossary defines the English phrase "illegitimate name" rather than the Latin equivalent. However, the Latin abbreviation is widely used by botanists and mycologists.

This is a list of terms and symbols used in scientific names for organisms, and in describing the names. For proper parts of the names themselves, see List of Latin and Greek words commonly used in systematic names. Note that many of the abbreviations are used with or without a stop.


  1. 1 2 3 4 5 6 7 McNeill, J.; Barrie, F.R.; Buck, W.R.; Demoulin, V.; Greuter, W.; Hawksworth, D.L.; Herendeen, P.S.; Knapp, S.; Marhold, K.; Prado, J.; Prud'homme Van Reine, W.F.; Smith, G.F.; Wiersema, J.H.; Turland, N.J. (2012). International Code of Nomenclature for algae, fungi, and plants (Melbourne Code) adopted by the Eighteenth International Botanical Congress Melbourne, Australia, July 2011. Regnum Vegetabile 154. A.R.G. Gantner Verlag KG. ISBN   978-3-87429-425-6.
  2. Brummitt, R.K. & Powell, C.E. (1992), Authors of Plant Names, Kew: Royal Botanic Gardens, ISBN   978-1-84246-085-6
  3. "Author Query Page". International Plant Names Index. Archived from the original on February 7, 2006. Retrieved 29 November 2010.