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).

The ICBN can only be changed by an International Botanical Congress (IBC), with the International Association for Plant Taxonomy providing the supporting infrastructure. The present edition is the St Louis Code (2000), available online. This is based on the decisions of the XVI IBC at St. Louis 1999. It was preceded by the Tokyo Code (1994), which is also available online. Following the XVII IBC in Vienna in 2005, the Vienna Code (2006) will be published. Each new edition supersedes the earlier editions and is retroactive back to 1753 (except where expressly limited).

Botanical nomenclature is independent of zoological and bacteriological nomenclature, which are governed by their own Codes (see Nomenclature Codes).

The ICBN applies not only to plants, as they are now defined, but also to other organisms traditionally studied by botanists. This includes blue-green algae (Cyanobacteria); fungi, including chytrids, oomycetes, and slime moulds; photosynthetic protists and taxonomically related non-photosynthetic groups. There are special provisions in the ICBN for some of these groups, as there are for fossils.

For the naming of cultivated plants there is a separate Code, the International Code of Nomenclature for Cultivated Plants. This gives supplementary rules and recommendations.

External links

• Tokyo Code (1994)
• St. Louis Code (2000)
• file

botanical nomenclature | Classification systems

Mezinárodní kód botanické nomenklatury | Internationaler Code der Botanischen Nomenklatur | Code international de nomenclature botanique | Codice Internazionale di Nomenclatura Botanica | Kod Antarabangsa Tatanama Botani | Botanische nomenclatuur | 国際植物命名規約 | ICBN