The International Code of Botanical Nomenclature (ICBN) is the set of rules and recommendations dealing with the formal botanical names that are given to plants. Its intent is that each taxonomic group ("taxon", plural "taxa") of plants has only one correct name, accepted worldwide. The value of a scientific name is that it is a label: it is not necessarily of descriptive value, or even accurate.
- The guiding principle in botanical nomenclature is priority. The ICBN sets the formal starting date of plant nomenclature at 1 May 1753, the publication of Species Plantarum by Linnaeus (or at later dates for specified groups and ranks).
- A botanical name is fixed to a taxon by a "type". This is almost invariably dried plant material and is usually deposited and preserved in a herbarium. Many type collections can be viewed online at the website of the herbarium in question.
Both these principles are regulated and limited. To avoid undesirable effects of priority conservation of a name is possible. Above the rank of family very few hard rules apply (e.g. see descriptive botanical names).