Publication of names and Rejection of names

For a successful publication of name, a scientific name must need an effective and valid publication by which this name will be acceptable in the whole world. The international code botanical nomenclature is based on the following sets of 3 principles, which are the philosophical basis of the code and provide guidelines for the taxonomists who propose amendments or deliberate on the suggestions for modifications of the code. 

Principles of ICBN

• Botanical nomenclature is independent of Zoological Nomenclature. The international code applies equally to the names of taxonomic groups treated as plants whether or not these groups were originally so treated. 
• The application of scientific names of taxonomic groups is determined by means of nomenclatural types. 
• Nomenclature of a taxonomic group is based upon the priority of publication. 
• Each taxonomic group with a particular circumscription, position and rank can bear only one current name, the earliest that is in accordance with the rules. 
• Scientific names of taxonomic groups must be in Latin form. 
• The rules of nomenclature are retroactive, unless expressly limited. 

Effective and Valid Publication of name

Effective Publication of Name

In biological nomenclature, It means that a set of rules which regulates how names of taxa have to be published to be recognized by the scientific community. 

e.g. A taxon name is not effective whether it was not published in a scientific journal ( means printed matters has to be distributed to the general public or botanical institutions with libraries accessible to botanists generally). 

Valid Publication of Name

A validly published name means, in the sense of botanical nomenclature, it fulfils all the requirements of ICBN ( International Code of Nomenclature for algae, fungi, and plants) for valid publication. 

• Those names were published earlier to 1st Jan 1935 are considered as valid even if the description or diagnosis were not in Latin. 
• Give a clear indication of rank. 
• Designated a type and its location.
• Published in a scientific journal. 
• Follow the rules of nomenclature which is decided according to the most recent code. 

Rejection of Name

The process of selection of the correct name for a taxon involves the identification of illegitimate names, those which do not satisfy the rules of botanical nomenclature. A legitimate name must not be rejected merely because it or it’s epithet, is inappropriate or disagreeable, or because another is preferable or better known or because it has lost its original meaning. 

• Nomen nudum – A name with no accompanying description. Many names published by Wallich in his catalogue ( abbreviated Wall. Cat.)  published in 1812 were nomen nudum. 

   These are either validated by another author at a later date by providing a description or if by that time the name has already been used for another species by some other author. The nomen nudum even if validated is rejected and a new name has to be found. 

     e.g.  Quercus dilatata Wall. a nom. nud. rejected and replaced by Q. himalayana bahadur, 1972.

• Name not effectively published, not properly formulated, lacking typification or without a Latin diagnosis. 
• Tautonym – whereas the Zoological Code allows binomials with identical generic names and a specific epithet (Bison bison), such names in botanical nomenclature constitute tautonyms (e. g. Malus malus)and are rejected.                       

   The words in the tautonym are exactly identical, and evidently names such as Cajanus cajan or Sesbania sesban are not tautonyms and thus legitimate. Repetition of a specific epithet in an intraspecific epithet does not constitute a tautonym but a legitimate autautonym. ( e.g. Acacia nilotica ssp. nilotica). 

•  Later homonym – Just as a taxon should have one correct name, the code similarly does not allow the same name to be used for two different species. Such as, if existing constitute homonyms. The one published at an earlier date is termed the earlier homonym and that at a later date termed as the later homonym. The code rejects later homonyms even if the earlier homonym is illegitimate. 

    e.g.  Ziziphus jujuba Lam. 1789 had long been used as the correct name for the cultivated fruit jujube. This, however, was ascertained to be a later homonym of a related species Z. jujuba Mill. 1768. Thus the binomial Z. jujuba Mill. is rejected and jujube finally named as Z. mauritiana Lam. 

• Later isonym – When the same name based on the same type,  has been published independently at different times by different authors, then only the earliest of these so-called ‘isonyms’ has nomenclatural status. The name is always to be cited from its original place of valid publication and later ‘isonyms’ may be disregarded. 

 e.g.  Baker (1892) and Christensen (1905) independently published the name Alsophila kalbreyeri as a substitute for A. podophylla Baker (1891) non Hook. (1857). As published by Christensen, Alsophila Kalbreyeri is later isonym of A. Kalbreyeri Baker. Without nomenclatural status. 

• Nomen ambiguum – A name is rejected if it is used in a different sense by different authors and has become a source of persistent error. The name Rosa villosa L. is rejected because it has been applied to several different species and has become a source of error. 

• Nomen Confusum – A name is rejected if it is based on a type consisting of two or more entirely discordant elements so that it is difficult to select a satisfactory lectotype. The characters of the genus Actinotinus, for example, were derived from two general Viburnum and Aesculus, owing to the insertion of the inflorescence of Viburnum in the terminal bud of an Aesculus by a collector. The name Actinotinus must therefore be abandoned. 

• Nomen dubium – A name is rejected if it is dubius, i.e. it is an uncertain application because it is impossible to establish the taxon to which it should be referred. Linnaeus (1753) attributed the name Rhinanthus crista-galli to a group of several varieties, which he later described under separate names, rejecting the names R. crista- galli L. Several later authors, however, continued to use this name for diverse occasions until Schwarz (1939) finally listed this as Nomen dubium, and the name was finally rejected. 

• Nomen Superfluum – A name is illegitimate and must be rejected when it is nomenclature superfluous when published, i.e. if the taxon to which it was applied – as circumscribed by its author – included the type of a name or epithet which ought to have been adopted under the rules. 

   e.g.  Physkium natans Lour. 1790 thus when transferred to the genus Vallisneria, the epithet natans should have been retained but de Jussieu used the name Vallisneria physkium Juss. 1826 a name which becomes superfluous. The species has accordingly been named correctly as Vallisneria natans (Lour.) 

• Name Based on monstrosity – A name must be rejected if it is based on a monstrosity. The generic name Uropedium Lindl. 1846 was based on a monstrosity of the species now referred to as Phragmidium caudatum (Lindl.) Royle, 1896. The generic name Uropedium Lindl. must, therefore, be rejected. The name Ornithogallum fragiferum Vill. 1787, is likewise, based on a monstrosity and thus should be rejected. 

SOURCES

• International Code of Botanical Nomenclature (https://home.kpn.nl/klaasvanmanen/icbn/0010Ch2Sec1a006.htm)

• International Code of Botanical Nomenclature (https://home.kpn.nl/klaasvanmanen/icbn/0001Contents.htm)
• Botanical Nomenclature: Northern Arizona University (http://www2.nau.edu/~gaud/bio300w/botnom.htm)
• International Association for Plant Taxonomy Institute (https://www.iapt-taxon.org/pages/regnumvegetabile)