Botanical nomenclature: ICBN rules, articles, recommendations and amendments of code

Botanical nomenclature: ICBN rules, articles, recommendations and amendments of code:-

International Code of Botanical Nomenclature (ICBN):- It is an international code or deed for writing the name of world flora. The naming of plants are following according to the rule of ICBN after its establishment. The ICBN only deals and control to the naming of plants but does not do any work on taxonomy. The head office of ICBN is situated at Atrect in the Netherlands. It has three departments namely, principles, rules and provisions for the governance of the code.

Principles of ICBN:- 

Principle 1:- Botanical nomenclature is independent of zoological and bacteriological nomenclature. 

Principle 2:- The application of names of taxonomic groups is determined by means of nomenclatural types. 

Principle 3:- The nomenclature of a taxonomic group is based upon priority of publication. 

Principle 4:- Each taxonomic group with a particular circumscription, position, and rank can bear only one correct name, the earliest that is in accordance with the Rules, except in specified cases. 

Principle 5:- Scientific names of taxonomic groups are treated as Latin regardless of their derivation. 

Principle 6:- The rules of nomenclature are retroactive unless expressly limited.

Rules and recommendation of ICBN:-

Rule 1. Rank of taxa:- The ICBN provides the series of rank with names which are the hierarchial catagories. The ranks, in descending sequence, provided by the Code are shown in the following table:

Taxonomic Ranks and mode of ending

Rule 2. The Type Method:- Names are established by reference to a nomenclatural type. Taxonomists use the type method as a legal device to provide the correct name for a taxon. The nomenclatural type of a species, a type specimen, is a single specimen or the plants on a single herbarium sheet.

Type specimen (herbarium sheet) is of different type:-

Holotype:- Herbarium sheet on which the first description of plant is based.

Lectotype:- In case of holotype is lost, second herbarium sheet prepared from the original plant is called lectotype.

Neotype:- In case holotype and original plant is lost then herbarium sheet prepared from some other plant of same species is called neotype.

Syntype:- In case holotype and original, plant is lost then many herbarium sheet prepared from many plants of same species is called syntype.

Isotype:- Duplicate of holotype - In presence of holotype a second herbarium sheet prepared from the original plant is called isotype.

Paratype:- Additional herbarium sheet used in the first description of plant is called para type. It is prepared from some other plant of same species having some variations.

Rule 3. Priority of Names:- Priority is concerned with the precedence of the date of valid publication and determines acceptance of one of two or more names that are otherwise acceptable. A name is said to be legitimate if it is accordance with the rules and illegitimate if it is contrary.

Rule 4. Effective and Valid Publications of Names:- The names of taxa must meet the requirement of the Code when it is published. It is effective under this code only when the distribution of printed is performed properly. It should be effectively published i.e. in a journal commonlyavailable to botanists andnot in alocal newspaperorin anyother printed form. It should be published inacorrect form i.e. Latinized with rank indicated and with Latin description (may be in brief). More detailed description is given in vernacular language. For the taxa of the rank of genus and below, nomenclature type must be indicated and location of the type also indicated. If the names are published effectively and validly using the rules of ICBN then the names are legitimate other wise they are illegitimate. The name of the newly described taxon is usually indicated by words sp.nov (species nova); gen.nov.(genus novum).

Rule 5. Citation of Author’s Name:- Thebotanical name is incomplete without author’s name. Accordingto article 46 it is necessaryto cite thenameof the authorwho firstvalidlypublishedthe name. Single author citation:-When single authoris involved in namingthe plant. Ifthe author’s name is too longitshould be abbreviated e.g.Solanum nigrum,L.L for CarolusLinnaeus. 

Double author citation:- When morethan one author isinvolved. If those authors isin different manner in differentconditions.

> When authors jointly published.

Polyalthia longifolia Bth & Hk

> If a genus or taxon of lower rank is altered in rank or position but retains its name, first authors name is cited in parenthesis followed by the author who has changed.

Leucaena latisiliqua (L)Gillis (1974)

> When first author has proposed a name but second author has validly published the name.

Cerasus cornuta Wallex Royal.

> When more than three authors are involved, citation is restricted to first author followed by et.al.

Rule 6. Conserved name (Nomina Conservanda):- Some of the names of taxa are not followed the rule of ICBN but they are using since a long time, hence ICBN has decided to retain the popular in addition to valid name.

Conserved Family

Rule 7. Priority of Publication:- Preference will be given who will publish earlier and only a single name is accepted for a taxon.

Advantages of using scientific name:-

• Avoid confusion concerning the names of plants. 

• Scientific names of plants are expressed in Latin because it is a international language

and was used by early scholars to express plant names. 

• It breaks the language barrier for communication as because it is universal 

• It is very much unique

Latin names of plants are italicized:- 

• Because it is conventional to italicize words and phrases that are expressed in a different language. 

• Example - The most commonly known cultivars of Acer rubrum (red maple) are “Red Sunset” and “Autumn Flame,” which are the most reliable for brilliant reds and a long-lasting display of foliage.

Recomendations of the ICBN:-

i. According to binomial system name of any species consists of two names i.e. generic and species name

ii. In plant nomenclature (ICBN), tautonyms are not valid i.e. generic name and specific name should not be same in plants e.g. Mangifera mangifera But tautonyms are valid for animal nomenclature (ICZN-International Code of Zoological Nomenclature) & Najanaja (Indian cobra), Raitus rattus (Rat).

iii. Length of generic mime or specific name should not be less than 3 letters and not more than 12 letters e.g Mangifera indica. Exception: Riccia paihankotensis – More than 12 letters According to ICBN this name is not valid but this name was proposed before 1961, so it is valid.

iv. First letter of generic name should be in capital letter and first letter of specific name should be in small letter. e.g Mangifera indica. But if specific name is based on the name of some person, its first letter should be in capital letter e.g. lsoetes pantii.

v. When written with free hand or typed, then generic name and specific name should be separately underlined. But during printing, name should be Italized.

vi. Name of scientist (who proposed nomenclature) should be written in short after the specific name e.g. Mangifera indica Lin.

vii. Name of scientist should be neither underlined nor written in italics, but written in roman, letters (simple alphabets)

viii. If any scientist has proposed wrong name then his name should be written in bracket and the scientist who corrected the name should be written after the bracket. e.gTsuga canadensis (Lin.) Salisbury

Note:- Linnaeus named this plant as Pinus canadensis

ix. Scientific names should be derived from Latin or Greek languages because they are dead languages.

x. Type specimen (Herbarium Sheet) of newly discovered plant should be placed in herbarium (dry garden). Standard size of herbarium sheet is 11.5 × 16.5 inches.

Amendments of code:-

1. Paris Code (1867):- The First International Botanical Congress was held at Paris in August, 1867, and was aimed at the standardization and legislation of proper nomenclature practices. About 150 American and European botanists were invited to attend the congress.

2. Rochester Code (1892):- In 1892 a batch of botanists headed by N.L. Britton met at Rochester, New York, in the United States and developed a set of rules to govern nomenclature. These rules, which are based, on modifications of the Paris Code, are commonly known as the Rochester Code and include some new recommendations which are as follows:

- Establishment of the type concept to ascertain the correct application of names.

- Strict adherence to the principles of priority.

- Acceptance of alternate binomials resulting from employment of the principles of priority, even if the specific epithet repeats the generic name.

- Interpretation of priority to apply to the precedence of a name in a publication in addition to the date of publication.

3. Vienna Code (1905):- The third International Botanical Congress was held at Vienna in June, 1905. The new changes included the:

- Establishment of Linnaeus Species Plantarum (1753) as the starting-point for naming vascular plants.

- Nomina generica conservanda by which generic names having a wide use would be conserved over earlier but less well-known names.

- Banning of tautonyms.

- Requirement that names of new taxa be accompanied by a Latin diagnosis.

4. American Code (1907):- Being dissatisfied with the results of the Vienna Congress, most proponents of the Rochester Code refused to accept the new rules and in 1907, they put forth a slight modification of the Rochester Code under the heading of the American Code. The first provision was that they would not subscribe to the principle of Nomina generica conservanda or of the requirement of Latin diagnosis, but they accepted the type concept.

5. Brussels Code (1912):- The Fourth International Botanical Congress was held at Brussels, 1910. The most significant decision made at this Congress was the establishment of different starting points for priority of names of non vascular plants, the recognition of value of type concept and classification of phraseology of the Vienna rules.

6. Cambridge Code (1935):- The basic differences between the Vienna Code and American Code was finally reconciled at the Fifth International Botanical Congress held in 1930 at Cambridge, England and it brought about harmony among the major botanical factions. The new rules legislated at Cambridge constituted the code of nomenclature that was truly international in name and function.

7. Amsterdam Code (1947):- At the Sixth International Botanical Congress, Amsterdam (1935), a few major changes in the rules was made. It was resolved that “from January 1, 1935, names of new groups of recent plants, except the Bacteria, are considered, as validly published only when they are accompanied by a Latin diagnosis”. An attempt to select a list of nomina specified conservanda was thwarted by an overwhelming vote.

8. Stockholm Code (1952):- The Seventh International Botanical Congress met at Stockholm in 1950. It introduced certain number of definitions on types. The word taxon was introduced for the first time to designate any taxonomic group or entity.

9. Paris Code (1956):- The Eighth International Botanical Congress was held in Paris in July, 1954 in which great emphasis was laid on types, but the rule of Latin came under fire. It decided that the code should be published in English, French and German languages.

10. Montreal Code (1961):- The Ninth International Botanical Congress held at Montreal in August, 1959 appointed a special committee to study the question of conservation of family names (nomina familiarum conservanda for Angiospermae as Appendix II was introduced). In this code, it was specified that the naming of fossil plants should follow the same lines as that of recent ones.

11. Edinburgh Code (1966):- The report of the special committee appointed during the ninth Congress was submitted at the Tenth International Botanical Congress held at Edinburgh in August, 1964.

12. Seattle Code (1972):- The Eleventh International Botanical Congress was held at Seattle in August, 1969 which proposed the Seattle Code which was edited by F.A. Stafleu and published in 1972. Most of the proposals submitted to the Eleventh Congress were concerned with refinements and increased precision.

13. Leningrad Code (1978):- The Twelfth International Botanical Congress was held in July, 1975 at Leningrad, Russia and its recommendations came out in 1978.

14. Sydney Code (1983):- The Thirteenth International Botanical Congress was held in August, 1981 at Sydney, Australia.

15. Berlin Code (1988):- This includes the proposals made at the Fourteenth International Botanical Congress at Berlin, Germany in 1986. Nomina specifica conservanda was for the first time introduced at this Congress.

16. Tokyo Code (1994):- The Fifteenth International Botanical Congress met at Yokohama, Tokyo in 1993. It has been translated into Chinese, French, German, Italian, Japanese, Russian and Slovak. In this code, extensive renumbering had taken place and therefore its preface included a tabulation comparing the placement of its provisions with those of the Berlin code.

17. St. Louis Code (1999):- This includes the proceedings of the Sixteenth International Botanical Congress, which was held at St. Louis, Missouri in July-August, 1999 and supersedes the Tokyo Code. Like the Tokyo Code, it is anticipated that the St Louis Code, too, will become available in several languages in due course.