International Code of Botanical Nomenclature

Nomenclature is the act of assigning a name to a plant, governed by the International Code of Nomenclature (ICN - renamed from the International Code of Botanical Nomenclature, ICBN, at the 18th International Botanical Congress, Melbourne, July 2011, specifically to separate the plant kingdom's naming rules from those of other organisms). ICN covers both living and fossil (extinct) organisms. Linnaeus first proposed elementary naming rules in 1737/1751 (Philosophia Botanica); A.P. de Candolle gave a detailed rule set in 1813 (Theorie elementaire de la botanique); the present ICN evolved from that same lineage of rules.

Six ICN principles: (1) botanical nomenclature is independent of zoological/bacteriological nomenclature; (2) the application of a taxonomic group's name is fixed by nomenclatural types; (3) naming is based on priority of publication; (4) each taxonomic group can bear only one correct name - the earliest name consistent with the rules; (5) scientific names are always treated as Latin regardless of their actual origin; (6) the rules of nomenclature apply retroactively unless expressly limited.

The International Botanical Congress meets roughly every six years to discuss and adopt naming-rule changes. The 2011 Melbourne Congress permitted electronic publication of new-taxon names, made Latin diagnosis optional (English is now permitted, Art. 39), adopted 'one fungus, one name' and 'one fossil, one name' (eliminating the old separate anamorph/telomorph naming for a fungus's asexual/sexual stages), and required new fungal names to register with a recognised repository (Index Fungorum or MycoBank). The 19th Congress (Shenzhen, China, 2017) has further changes still pending publication. …