In botanical nomenclature, author citation refers to 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 Botanical Nomenclature (ICBN). In botany, it is customary (though not obligatory) to abbreviate author names according to a recognised list of standard abbreviations. 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 author(s) of the original genus placement and those of the new combination are given (the former in parentheses).
There are diffences between the botanical Code and the normal practice in zoology. For example, in zoology the publication year is given following author name(s) 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 is customary to cite the author of a scientific name at least the first time this is mentioned, so as (for example) to be clear which instance of a named taxon is being referred to, especially on account of the presence of homonyms of some names in biology (for example Ficus L., the fig tree genus, vs. Ficus Röding, 1798, a genus of molluscs). Rules and recommendations for author citations in botany are covered by Articles 46-50 of the International Code of Botanical Nomenclature (ICBN). 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.
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. When citing a botanical name including its author, the author's name is often abbreviated. To encourage consistency the International Code of Botanical Nomenclature (ICBN) recommends the use of Brummitt & Powell's Authors of plant names (1992), where each author of a botanical name has been assigned a unique abbreviation. These standard abbreviations can be found at the International Plant Names Index.