International Code of Botanical Nomenclature (ICBN): History, Principles and Aim
Posted on : 24-11-2017 Posted by : Admin


Introduction to ICBN

The process of naming plants based on international rules proposed by botanists to ensure stable and universal system is called botanical nomenclature. It is an essential process to overcome the problems of common names. The botanists agreed to lay down certain rules and conditions. The main suggestion was that language should be in Latin as it is not a national language of any country and moreover it is dead language. A lot of previous literature is written in Latin. The ICBN is an agreement between botanists around the world to follow Binomial system of naming.


History of ICBN

Before the middle of 18th century the names of plants were polynomials consisting of several words. Linnaeus proposed elementary rules in his book named ‘Philosophia botanica’ in 1751. In 1813 A.P. de Candolle proposed details of the rules regarding plant nomenclature in Theorie elementaire de la botanique. In 1867, Alphonse de candolle, son of A.P. de candolle convened a meeting of all botanists to present these rules. This first Botanical congress was held at Paris and the laws framed therein were called as Paris code.

In 1930, the fifth International Botanical Congress (IBC) was held in England to frame rules and regulations for naming plants. In July 1975, twelfth meeting was held at Leningrad, USSR. Based on the resolutions of these meetings, the existing system of International Code of Botanical Nomenclature (ICBN) was adapted from 1978. The IBC meets every 5 to 6 years to decide any additions or changes in the naming and numbering of plants. The 18th IBC congress was held at Melbourne in 2011 and the latest 19th IBC was held in Shenzen, China in July 2017.


Principles of ICBN

  1. Botanical nomenclature is not dependent of Zoological nomenclature and is different.
  2. The code of botanical nomenclature applies equally to all names of taxonomic groups which are treated as plants.
  3. The names of taxonomic groups are determined by nomenclatural types.
  4. When a species is described as new, the author must indicate the type of specimen on which new species is based.
  5. The nomenclature of taxonomic group is based on priority of publication.
  6. Each taxonomic group with a particular circumscription, position and route can bear only one correct name that is in accordance with the rules except in specific cases.
  7. Scientific names are treated as Latin irrespective of their derivation.
  8. The rules of nomenclature are retroactive unless expressly limited.


The aim of ICBN

  • To provide stable method of nomenclature
  • To avoid and reject the names which cause confusion.
  • To avoid useless creation of names

The code is divided into rules and recommendations. Examples are added to the rules and recommendations to illustrate them. The objective of the rules is to bring past nomenclature into order and to follow rules for future nomenclature. The objective of the recommendations is to bring uniformity and clearness in future nomenclature.


Ranks and ending of taxa names

The plant kingdom is divided into number of categories which differ in their rank and size. In biological classification, rank is the relative position in a taxonomic hierarchy. Examples of taxonomic ranks are species, genus, family order etc. Each rank subsumes under it a number of less general categories.

  • The basic unit in the classification of plants is Species. A species is defined as a single type of living organisms.
  • The group of closely related species is known as Genus.

For example, the genus Hibiscus is made up of closely related species, which differ in their vegetative characters.

  • The group of closely related genera is known as family. Scientific name of a family usually ends in ‘-ceae’.

For example, Hibiscus belongs to family is Malvaceae, it consists of several genera like Gossypium (cotton), Abelmoschus (lady’s finger) etc.

  •  The group of closely related families is known as order. Scientific name of an order ends in ‘-ales’.

For example, Hibiscus order is Malvales which includes family like Malvaceae, Dipterocarpaceae.

When these groups are large, they are subdivided as suborder, subfamily, sub-tribe, sub-genus. They all end in a standardized manner as shown below,

Rank Ending of names
Division -phyta
Class -opsida
Sub class -idea
Order -ales
Sub order -ineae
Family -aceae
Sub family -oideae

Some of the families do not end with -aceae, so they are provided with alternative names like,

  • Cruciferae – Brassicaceae
  • Compositae – Asteraceae
  • Graminae – Poaceae
  • Guttiferae – Clusiaceae
  • Leguminosae – fabaceae
  • Palmae – Arecaceae
  • Umbelliferae – Apiaceae


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  • aubid malik on Feb 16, 2018 at 02:01 pm

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    • StudyandScore  on Feb 25, 2018 at 04:17 pm

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  • Nikunj Jain on Mar 31, 2018 at 09:48 am

    thank you