Botany Notes “Nomenclature, What is Living” Chapter 1 for Class 12-CBSE

NOMENCLATURE

There is a need to standardize the naming of living organisms, such that a particular organism is known by same name all over the world. A variety of nomenclatural methods are described below :

1. Vernacular name : Names in local or common language are called vernacular names. So, many vernacular names exist for an organism in different languages. These may vary from place to place.
2. Scientific names : These names were based on definite rules and criteria. These are of following type :
   1. Polynomial nomenclature
   2. Trinomial nomenclature [both given in content builder]
   3. Binomial system of nomenclature : Swedish naturalist Carolus Linnaeus established binomial nomenclature though, it was first proposed by Casper Bauhin in his book PINAX. In binomial nomenclature, the first word is a generic name and second word is a specific epithet like Mangifera indica Linn. After end of biological name , the name of author is written in abbreviated form who gave the name of the organism. Scientific names are in Latin, because Latin was the language of scholars at the time of Linnaeus, and no change is possible in the language because this language ahs no synonyms. Linnaeus gave some principles of the binomial nomenclature in Philosophia Botanica. But the nomenclature was used first in Species Plantarum (1753). Where names and description of 5900 species of plants were given. Later the published Systema Naturae (1758), where 4326 species
3. International code of Nomenclature

Scientific  names have been standardized through some international agencies, viz., international Code of Botanical Nomenclature (ICBN, 1961) and International Code of Zoological Nomenclature (ICZN, 1964), International Code for Nomenclature of Bacteria (ICNB), International Code of Nomenclature for Cultivated Plants (ICTV).

1. Rules for Binomial Nomenclature

ICBN and ICZN formulated certain rules and regulations for giving scientific names to all organisms. These rules are as follows :

1. The valid name of an organism has two components, i.e., a generic name and a specific epithet. The generic name should begin with a capital letter and species name should begin with a small letter.
2. Both the words in a biological name when handwritten are separately underlined or printed in italics to indicate their Latin origin.

• The name of the author should be written after the scientific name in Roman type with capital letter without any comma in between and is written in an abbreviated form, e.g., Homo sapiens Linn. Is the complete scientific name for modern man. This shows that Linnaeus was the first scientist who named man as Homo sapiens.

1. Scientific names should not contain less than three and more than twelve letters.
2. Principle of priority : it is the most important of all the rules of ICBN. If first name given to the organism is valid (in terms of rules), that will be considered at the first preference. Any other valid name given after that will be considered as synonym. No names are recognized prior to those used by Linnaeus in 1758 in the 10^th edition of Systema Naturae for animals and 1753 for plants.
3. All the three words (generic name, species epithet and author citation) collectively form binomial epithet.

• If a species name has two or more words in its name, a hyphen is put between these. Such names are compound specific names (e.g., Hibiscus rosa –  sinensis).