International Code of Botanical Nomenclature Ultimate Guide

International Code of Botanical Nomenclature

Naming plants is an age-old practice. The process of giving names to plants is called nomenclature.

Common Names

These are names given to plants by different human groups in various languages or in English. The biggest problem with common names is that they are not universally understood by everyone or all scientists.
For example, if we say “Jalkumbhi” (Water hyacinth), people in England, America, or China may not understand it. But if we refer to the plant as Eichhornia, it will be understood by scientists across all countries.

Some other examples of common/local names with their scientific names:

• Kachnar – Bauhinia
• Saptaparni – Alstonia
• Satmool – Asparagus
• Sarpagandha – Rauvolfia serpentina

Some common names have even been adopted as scientific names, such as:

• Putranjiva – originally a Sanskrit name, now used scientifically
• Anthocephalus cadamba – mentioned in ancient Indian texts and now a recognized scientific name.

Since common names are not universally understood, there arose a need for a standardized scientific method of naming based on an international code.

Development of Scientific Names

Scientific names were initially based on polynomial nomenclature, where plant names were long and complex, e.g.:

• Salix plumilangustifolia alterl
• Lichenus alpina linifolia multiflora

These were complicated and impractical for scientific use.

Then came Carl Linnaeus, who in 1753 introduced the binomial nomenclature system in his book Species Plantarum. He also mentioned naming principles in his earlier work Fundamenta Botanica and later Philosophica Botanica. The naming system he used was later referred to as “code”.

In 1813, De Candolle published Théorie élémentaire, and in 1821, Steudel published Nomenclator Botanicus, both promoting standardized nomenclature.

Key Points of Binomial Nomenclature

1. Each plant has two names – the genus and the species.
   E.g. Mangifera indica: Mangifera is the genus, indica is the species.
2. After the species name, the name of the person who first described the plant must be included.
   E.g. Mangifera indica L. – “L” stands for Linnaeus.
3. Genus names are in Latin or Latinized, and begin with a capital letter. Species names can be based on a person, region, or trait, and start with a lowercase letter.
   E.g. Putranjiva roxburghii, indica, alba.
4. Genus name comes first, followed by species name.
5. A genus name is unique, but the same species name can appear in different genera.
   E.g. Mangifera indica and Tamarindus indica.
6. Some plants may have trinomial names, e.g. Puccinia graminis f. tritici.

Botanical Code

As knowledge of plants grew, the need for a standard naming system became necessary. Linnaeus first followed the rules in Critica Botanica (1737) and later expanded them in Philosophia Botanica (1751). Later developments included:

Development of Botanical Code:

• 1867 – De Candolle proposed rules known as De Candolle’s Rules or Paris Code.
• 1892 – Rochester Code
• 1905 – Vienna Code (3rd International Botanical Congress)
• 1907 – American Code (a revision of Vienna Code)
• 1918 – Type Basis Code (by Botanical Society of America)
• 1935 – Amsterdam Congress
• 1950 – 7th International Botanical Congress, Stockholm
• 1954 – 8th Congress, Paris
• 1959 – 9th Congress, Montreal
• 1964 – 10th Congress, Edinburgh (gave final approval to “Rules of Latin”)
• 1969 – 11th Congress, Seattle – Introduced Tautonyms (e.g. Malus malus)
• 1975 – 12th Congress, Leningrad – Resulted in the Leningrad Code with 3 parts:
  1. 6 basic principles
  2. 75 articles
  3. Detailed discussion on code revisions

Rules of the Code

Each species is the basic unit of classification. It is part of a hierarchy of taxonomic ranks. Certain suffixes are used for different taxonomic levels.

Changes in family names:

• Palmae → Arecaceae
• Cruciferae → Brassicaceae
• Leguminosae → Fabaceae
• Umbelliferae → Apiaceae
• Labiatae → Lamiaceae
• Compositae → Asteraceae

Typification

A type specimen is a reference plant, often pressed in a herbarium, used to define the name of a species.

• Holotype: The main specimen used for naming.
• Isotype: Duplicate of the holotype.
• Syntype: Multiple specimens when no holotype is designated.
• Lectotype: Chosen if the holotype is lost.
• Paratype: Other specimens cited but not the holotype.
• Neotype: Chosen when all previous types are lost.

Principle of Priority

If more than one name exists for a species, the first validly published name is accepted.

Example:

• Ruppia maritima L. and Ruppia rostellata Koch – both refer to the same plant, but R. maritima is accepted due to earlier publication.

Synonyms:

• Nomenclatural synonym – same species with different names.
• Taxonomic synonym – different views on classification.

Valid or Accepted Publication

A name is valid only when:

• It is printed and distributed to botanical institutes.
• It follows the rules of the code.

Scientific Names Format

Scientific names include:

1. Genus name
2. Species name
3. Author’s name

If multiple authors are involved:
E.g. Offincla colardi Britt et Ross

If a species is moved to another genus, the original author’s name is placed in brackets, followed by the new author:
E.g. Linaria scurium (L.) Mill.

Retention and Rejection of Names

• The oldest valid name is retained when merging taxa.
• A name may be rejected if it is meaningless or not accepted.

Cultivated and Hybrid Plants

Nomenclature codes also apply to cultivated plants, even though Latin names are not compulsory. Special rules are provided for hybrid plant names.