Binomial Nomenclature - Codes

Codes

From the mid nineteenth century 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, the International Code of Nomenclature for algae, fungi, and plants (ICN) 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, although it is also used by zoologists. Since 1953, "binominal nomenclature" is the technically correct term in zoology. A binominal name is also called a binomen (plural binomina).
• Both codes consider the first part of the two-part name for a species to be the "genus name". In zoological code (ICZN), the second part of the name is a "specific name", or in the botanical code (ICN) a "specific epithet". Together, these two parts are referred to as a "species name" or "binomen" in the zoological code; or "species name", "specific name", or a "binary combination" in the botanical code.
• The ICN, 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 binomial 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 Clerck's Aranei Svecici). Bacteriology started anew, with a starting point on 1 January 1980.

Unifying the different codes into a single code, the "BioCode", has been suggested, although implementation is not in sight. (There is also a code in development for a different system of classification which does not use ranks, but instead names clades. This is called the PhyloCode.)