This is a part of online classes for the Botany undergraduate students of Government First Grade College Yelahanka Bangalore on 5 -8 October 2020

1. PLANT NOMENCLATURE
Dr P B MALLIKHARJUNA
Associate Professor
GFGC YB

2. Plant nomenclature is an important aspect of Taxonomy. Naming of plants based on certain
rules proposed by the International Botanical Society over a period is called Plant
Nomenclature. These names are usually termed as the botanical names or the scientific
names. These are evolved as the Binomials from the Polynomials and the Vernaculars through
the ages.

3. BINOMIAL NOMENCLATURE
The method of giving scientific names to plants
and animals with the name consisting of two parts
is binomial nomenclature. Therefore, the scientific
names of organisms are always binomials.
Naming the organisms become essential mainly for
three reasons
•To remember the particular organisms we studied
•To communicate the same with the others and
•To maintain the scientific documentation.

4. Giving names to organisms is in practice since time
immemorial. However, the names used in earlier days
are vernacular names in local languages and such
names have many defects for example
•They do not remain same throughout the world.
•They tend to change from place to place and
from language to language
•In some instances, a common name is applied to
different plants and the same plant may be called
by different names.
•Common names are not available to all kinds of
plants.

5. Therefore, there was a necessity to give scientific names. However, the
first introduced scientific names were polynomial .These were more
lengthy and descriptive and difficult to remember For example,
Gravelliarobusta grandiflora australiana.Later binomial system was
proposed. Where the name consisted only of two parts. The first part
of the name is the genus name and the second part is the species name
or specific epithet. This binomial system was actually proposed for the
first time by “Casper Bauhin”( 1623) but he did not make its application
compulsory. Later, it was Linnaeus (1753) a Swedish botanist who
adopted the binomial nomenclature in his “Species plantarum.1753”, and
hence the credit went to Linnaeus. Therefore, 1st May 1753 is regarded
as the beginning date of the scientific names of all living beings including
plants. Latin language is chosen for scientific names.

6. Certain rules are to be followed in giving the binomials. The first
letter of the genius should be capital and the first letter of the
species should be a small letter for example Mangifera indica,
Cocos nucifera etc. Whenever, these names are hand-written or
type written they are to be underlined. The names should be in Latin
language or if the names are derived from any other source, they
are to be latinised. The genus name always be a noun, the species
name will be an objective, and hence it usually tells as a character
or home of the place. For example Solanum nigrum (nigrum-black),
Mangifera indica (Indica-India). The scientific names are usually
followed by the name of the author in abbreviation validly published
it for the first time. Example Mangifera indica L.(L=Linnaeus).

7. ICBN
International code of botanical nomenclature (ICBN) or the code is
the premier constituent body of the international botanical
society/Congress. Its main job is to look after the plant nomenclature
of both extant and extinct taxa. The first code was held in Paris,
France during 1867 under the guidance of A.P. de Condolle. The basis
for the code has been drawn from de Condolle's
“Theorie elementiare de la Botanique” and also from the Critica
Botanica, Fundamenta Botanica and Philosophia Botanica of Linnaeus.
Since then for every 6 years the International Botanical Congress
(IBC) meeting is held to discuss the various aspects of nomenclature
and publishing as the code. The latest edition of code i.e., 19th edition
was held in Shenzen, China (2017) recently and which supersedes all
previous editions.

8. The code/ICBN is mainly consisting of the preamble and three divisions as follows

9. THE PREAMBLE
Botany requires precise and simple system of
nomenclature used by Botanists in all countries.
AIM OF THE CODE:
•It aims at the provisions of a stable method of naming
taxonomic groups, avoiding or rejecting the use of
names, which may cause error or ambiguity.
•Further, it aims at the avoidance of the useless
creation of new names.

10. Division I-Principles: these will form the basis of the system of
botanical nomenclature and has 6Principles namely,
Principle I: Botanical nomenclature is independent of zoological and
bacteriological nomenclatures. Further, the code applies equally to
names of taxonomic groups treated as plants whether or not these
groups were originally so treated.
Principle II: The application of names of taxonomic groups is
determined by means of nomenclature types.
Principle III: The nomenclature of a taxonomic group is based upon
the priority of publication.
Principle IV: 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 V: Scientific names of taxonomic groups are treated as
Latin regardless of their derivation.
Principle VI: The rules of nomenclature are retroactive unless
expressly limited.

11. Division II- Rules and Recommendations: The detail provisions of
the code are divided into Rules in the form of Articles (62) and which are
binding. The main objective of rules is to put the nomenclature of the past
into order and to provide that for the future.
Whereas, Recommendations are subsidiary points and which are non-
binding but to be preferred. The main objective is to bring about greater
uniformity and clarity especially in future nomenclature.
This division included 7 Chapters, 16 Sections and 62 Articles.
Chapter I deals with taxa and their ranks (Art 1-5)
Chapter II deals with typification (Art.6-10) and rule of priority
( Art. 11-15)
Chapter III deals with nomenclature of taxa according to their ranks
(Art. 16-28)
Chapter IV deals with Effective and Valid publication (Art. 29-50)
Chapter V deals with rejection of names (Art. 51-58)
Chapter VI deals with the names of fungi with pleuromorphic life cycle
(Art 59) and
Chapter VII deals with the Orthography and gender of names
(Art: 60-62)

12. Division III: includes provisions regulating the governance
of the code. It has five appendices namely
Appendix I: names of hybrids
Appendix IIA/B: Nomina familiarum conservanda
Appendix IIIA/B: Nomina generica/specifica conservanda
et rejicienda
Appendix IV :Nomina utique rejicienda
Appendix V: Opera utique oppressa

13. RULE OF PRIORITY:
According to the code /ICBN rule ”Each family or taxon of lower rank
with a particular circumscription, position and rank can bear only one correct
name. And, it is the earliest legitimate one which is validly published with
the same rank (Art 11). Further, the name of a taxon has no status under
this code unless it is validly published (Art 12)”.
The date of valid publication is 1stMay 1753 of Linnaeus’ Species
Plantarum.
For instance, when there are several names for a taxon, the earliest
name, which is validly published, is regarded as the correct name. Thus, the
rule of priority gives stability to the plant nomenclature.
Ex: Cleome gynandra Linn(1753)
Cleome pentaphylla Linn (1762)
Gynandropsis pentaphylla DC(1824)
The above three names are existing for a single taxon. Of these, the
earliest one i.e., Cleome gynandra is valid and legitimate name according to the
the Rule of priority. While the other two are synonyms and these are
conserved in the appendix IIIB of the Code (Nomina specifica conservanda
et rejicienda).
Finally, the application of both conserved and rejected names, are
determined by the nomenclature type (Art 14).

14. Effective and valid publication:
According to the Code/ICBN, the author to make it, as a correct or
legitimate name must effectively and validly published the scientific
name of a given taxon.
In general, Effective publication deals with standards applicable to the
media. In which the names are published and not to the names
themselves (Article 29).Whereas, valid publication deals with standards
applicable to the names themselves (Article 32 – 45).
There are four general criteria for publication of a name.
•The name must be effectively published. That means it must be
published in a journal commonly available to botanists such as Rheedea
(national level) or TAXON or Systematic Botany( international level).
•The name must be published in the correct form, i.e., properly
Latinised, with rank indicated (Ex. as “sp.nov” or “gen.nov”). Such a name
in correct form is known as the admissible name.

15. •The name must be published with a Latin description or diagnosis or
with a reference to such. The Latin diagnosis may be a brief. For
instance, listing how the new taxon is different from a similar
related taxon.
•A nomenclatural type must be indicated.
Finally, the term “PROTOLOGUE is “everything associated with a
name at its valid publication i.e., description or diagnosis,
illustrations, references, synonyms, geographical data, citation of
specimens, discussion and comments”.
A full citation of a scientific name may include the authorship and
the journal, volume, page numbers and data of publication.
For ex: A complete citation for the new species (sp.nov).
Cited as: Perityle vigilans Spellenb & A.Powell, Syst. Bot. IS:
252.1990.

16. TYPIFICATION
( Type Method)
According to the Code/ICBN (Article 7-10), the application of names
to taxonomic groups is governed by nomenclatural types. This rule
previously applicable to the rank of family or below. However, now it is
extended to the names of taxa of higher ranks when the names are
ultimately based on generic names.
Nomenclature type: it is the representative element of a taxon.
When any author publishes the account of species, the original plant
on which the description is based, is deposited in any standard
Herbarium.This type specimen becomes the nomenclatural type of
that specimen and is associated ever with the specific name given on
its basis.
Type specimen: is the one that is ultimately associated with the
name of a taxon.The type for a genus is a species, for a family it is a
genus, and for an order, it is a family.

17. Ex: Rosa indica (Species)Rosa (Genus)Rosaceae (Family) Rosales
(Order)
Magnolia grandiflora (species)Magnolia (Genus)Magnoliaceae
(Family)Magnoliales (Order)
There are several types of nomenclatural types existing such as
Holotype
Isotype
Syntype
Paratype
Lectotype
Neotype

18. HOLOTYPE : is the type specimen or other element used or
designated by the author in the original publication as the main
nomenclatural type. At present, it is essential that a holotype
designated for a newly described species be deposited in a national
herbarium like the Central National Herbarium(CAL), Calcutta of
the BSI.
ISOTYPE: is the duplicate specimen of a holotype. There are plants
forming part of the same gathering as the holotype and gathered at
the same time.In the absence of holotype, isotype will serve as the
nomenclatural type.

19. SYNTYPE: is one or two or more specimens studied and cited by the
author when the holotype is not designated by him.
PARATYPE: is a specimen cited with the original description in
addition to the holotype.When the author fails to designate a holotype
or the holotype is missing, a lectotype or neotype is selected to serve as
a nomenclatural type.
LECTOTYPE: is a specimen selected from those cited by the author
with the original description.
NEOTYPE: is selected only when all the original specimens collected
and cited by the author missing.

20. For example :Impatiens thomsonii Hook.f., is a member of the family
Balsaminaceae and its description is given in the Flora of British India.
The author (J D Hooker) has cited three specimens on which the
description was based on.
• Collected by Thomson from Piti and Kunawar.
•Collected by Strach.and Wint.from the Kumaon and Garhwall hills.
•Collected by JD Hooker from Sikkim.
Hooker stated that specimen 3 of the above is the nomenclatural type
(i.e., Holotype).Specimens 1 and 2 are the Paratype. If Hooker had not
designated the 3rd specimen as holotype, then all three were Syntypes.
One of these syntypes can serve as a Lectotype, if the type holotype is
missing. If all 3 specimens are destroyed for some reason, then the 4th
specimen (Collected by Wallich from Sikkim, which does not find
mention in Hookers description, will be treated as a Neotype.