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).
Problems include: Rules and recommendations for author citations in botany are covered by Articles 46–50 of the International Code of Nomenclature (ICN).
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.
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.
to the botanist Diederich Franz Leonhard von Schlechtendal; these authors jointly described this species (and placed it in the genus Rubus) in 1827.
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: 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.
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.
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: 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.
for exclusis varietatibus, indicates that this taxonomic concept excludes varieties which other workers have subsequently included.)