Principles and Rules of ICBN, IBC, The Hisory of ICBN

This PPT offers a bird's eye view of ICBN and its different rules along with regulations for the naming of plants. It also highlights the history of IBC and its contribution to plant taxonomy.

1. PLANT TAXONOMY
Welcome to
PRINCIPLES AND RULES ( ICN)
By
Dr. N. Sannigrahi, Associate Professor,
Department. Of Botany,
Nistarini College, Purulia, (W. B), India

2. A PLEASURE OF NATURALISTS TO KNOW THE PLANTS

3. RETROSPECTS OF ICBN
Namingoftheplantsanditidentificationaretheurgeofallnaturalists,
Vernacularnamesarenotwidelyaccessibleandnotavailabletoallplants,
Commonnamedonotprovidesufficientdesiredinformationinthisregard,
Thetaxonomichierarchyisnotprovidedbythecommonaswellasvernacular
namesasassignedforplantsfromdifferenttimeandplaces,
Manycommonnamesmayoccurforthesamespeciesinthesamelanguagein
thesameordifferentlocalities,
Keepingallthesedisturbancesinmindregardingplantnaming,itbecomes
essentialtoassignaparticularnameforaparticularplanttomakeholisticand
easilyaccessible.,
ICBNistheuniformdomainthatcanaddressalltheaforesaidissues.

4. ICN OR ICBN
Linnaeusin1737&1751proposedtheelementaryrulesofnamingplants
in‘PhilosophiaBotanica’.Thenin1813,A.P.deCandollesetfortha
detailedrulesregardingplantsnomenclatureinhisTheorieselementirede
labotanique.ThesamerulesofLinnaeus,A.P.deCandolleandhisson,
AlphonsedeCandollewerelaterevolvedintoourpresentInternational
CodeofBotanicalNomenclature(ICBN).
AlphonsedeCandolleconvenedthefirstInternationalBotanicalCongress
in1867inPariscalledParisCodeattendedbybotanistsfromseveral
countries.Theyadoptedasetofrulesofplantnomenclature,mostof
whichwereproposedbyA.deCandolle.SubsequentmeetingsofICBN
heldin1892(Rochestercode),1905(ViennaCode),1907(American
Code)andageneralagreementcameintotheforceonIBCatCambridge.

5. IBC CHRONOLOGY
Cambridge(1930)-”forthefirsttimeinbotanicalhistory,acodeof
nomenclaturecameintobeingthatwasinternationalinfunctionaswellas
inname”.ThisiscalledICBN.Thenfrom1930,anumberofIBCarebeing
heldasperorderfortheadoptionofrulesandrecommendationsinPlants
taxonomy.
1935-Amsterdam,
1850-Stochholm,
1954-Paris,
1959-Montreal,
1964-Edinburgh,
1969-Seattle,
1975-Leningrad,
1981-Sydney,
1987-Berlin,

6. IBC CHRONOLOGY
1993-Tokyo,
1999-St.Louis,
2005-Vienna
2011-Melbourne
2017-Snenzhen,
2024-Madrid
TheIBChasthepowertoaltertheICN(InternationalCodeof
Nomenclatureforalgae,fungi,andplants,whichwasrenamedfromthe
InternationalCodeofBotanicalNomenclature(ICBN)attheXVIIIIBC.
FormallythepowerresideswiththePlenarySession;inpracticethis
approvesthedecisionsoftheNomenclatureSection.TheNomenclature
SectionmeetsbeforetheactualCongressanddealswithallproposalsto
modifytheCode:thisincludesratifyingrecommendationsfromsub-
committeesonconservation.Toreducetheriskofahastydecisionthe
NomenclatureSectionadoptsa60%majorityrequirementforanychange
notalreadyrecommendedbyacommittee.

7. PRINCIPLES
I.Botanicalnomenclatureisindependentofzoologicalnomenclature.The
codeappliesequallytonamesoftaxonomicgroupstreatedasplants
whetherornotthesegroupswereoriginallysotreated(Plantsdonot
includeBacteria).
II.Applicationofnamesoftaxonomicgroupsisdeterminedbymeansof
nomenclaturetypes.
III.Thenomenclatureofataxonomicgroupisbaseduponpriorityof
publication.
IV.Eachtaxonomicgroupwithaparticularcircumscription,position,and
routecanbearonlyonecorrectname,theearliestthatisinaccordancewith
therules,exceptinspecificcases.
V.ScientificnamesoftaxonomicgroupsaretreatedasLatinregardlessof
theirderivation.
VI.Therulesofnomenclatureareretroactiveunlessexpresslylimited.

8. PRINCIPLES OF ICBN

9. RULES AND RECOMMENDATIONS OF ICBN
AccordingtotheICBN(1983),thecode“aredividedintoRules,setoutin
Articles,andRecommendations”.AsmentionunderpointNo.4ofthe
Preambleof1983ICBN”TheobjectoftheRulesistoputthe
nomenclatureofthepastintoorderandtoprovideforthatofthefuture,
namescontrarytoarulecannotbemaintained”.
TherulesandrecommendationsofICBNapplytoallorganismstreatedas
plants(includingfungibutexcludingbacteria),whetherfossilornon-fossil.
Nomenclatureofbacteriaisgovernedbyaseparatecodecalled
InternationalCodeofBacterialNomenclature(ICNB)andsoasto
cultivatedplantsbyICNCP.
ItisstatedunderpointNo.10ofICBNthatthelatest“editionoftheCode
supercodesallpreviouseditions”

10. SOME IMPORTANT RULES
1.Ranks and Endings of Taxa
2. Principle of Priority,
3. Type Method,
4. Citation of Author
5. Synonyms and related Definitions
6. Names of Cultivated plants,
7. Latin Diagnosis,
8. Effective & Valid publication,
9. Choice of Names when the Taxon Rank is Changed
10.Choice of Names when same –rank Taxa are united,
11. Retention of Names of Divided Taxa,
12. Retention of Names of Taxa on Transference
13. Rejection of Names
14. Names of Different Taxa.

11. 1.RANKS AND ENDINGS OF TAXA
Thesystemofclassificationprovidesahierarchicalarrangementofthe
ranksandthisisverymuchnecessarytoknowtheassignmentstatusof
thegiventaxa.Generally,thereareaboutsevenmainobligatoryranksof
taxaareusedinordertodesignatethemandeachoneisidentifiedbythe
particularsuffixusedastheendingsoftheeachtaxa.Theobligatory
ranksareasbelow:
Kingdom,(regnum),Division(Diviso),Class(classis),Order(ordo),
family(familia),Genus(genus)andSpecies(species).Thesuffixesare
usedasstatedbelow.
Division-Phyta,
Sub-division-phytina,
Class-opsida,
Sub-class-opsidae,
Order-ales,
Suborder-ineae
Family-aceae

12. RANK AT THE LEVEL OF GENUS & SPECIES
Asperpreviousinformationisconcernedabouttheendingsoftherankofthe
taxa,differentsuffixesareusedtodesignatethem.Thequestionariseshowthe
nameofthegenusandspeciesaredesignedandwhetherdotheyfollowany
strictruleinthisregardfornamingthem?Theanswerliesintheunderstanding
ofthegenusandspeciesnamedeterminedasstatedbelow:
A.Genericname:
i.Commemorationofaperson-Thenamesmaybededicatedtogreat
personalitiesindifferentfieldsasstatedbelow:
BauhiniafromBauhin,DarwiniafromDarwin,VictoriafromtheQueen
VictoriaofEngland,WashingtoniafromGeorgeWashington.Whenthenames
areusedforgenus,ittakesfamineformandsomerulesarefollowedinthis
regard.LikeOttobecomesOttoetc.

13. RANK AT THE LEVEL OF GENUS & SPECIES
ii.Basedonplace-someplacesmaybeassociatedwithgenuslike
CaucasisfromCaucasusinRussia,SalvadorfromELSalvador,
ArabisfromArabia,SiberiafromSiberiaofRussiaetc.
iii.Basedonimportantcharacter-Zanthoxylumfromyellow
wood,HepaticafromLiver-like,HygrophilaformMarshyhabit,
TrifoliumfromTrifoliateleavesetc.
Aboriginalnames-Withoutalternationofendingingenus,the
namehasbeendesignedasstatedbelow:
Narcissus-aGreeknameofdaffodilsafterthenameofGreekgod,
Ginkgo-aChinesename,
Vanda-Sanskritword,
Sasa-aJapaneseoriginalname,
Putranjiva-amythologicalnameetc

14. SPECIES NAME
Alltheepithetusuallystartswithsmallletteranditmayderivefromanyor
compoundarbitrarily.
Nameofaperson:WallachiafromWallchi,HookariforHookeretc(Ifitis
becomesgenitiveorpossessiveform,itbecomescapital).
Formedbyaplace-indicafromIndia,kasmiriansisfromKashmir,etc.
Basedoncharacter-albaoralbusoralbumforwhite,cultivatedspeciesas
sativa,cordifoliaforcordateleaves.
Nouninapposition-Someepithetsmayhavetheirowngenderastheyarenoun
inapposition,innominativecase.PyrusmalusisbasedonGreeknamemalus
forcommonpeople.
Someotherspecificepithetsarerara(rare),vulgaris(common),autmnalis(
autumn),ethnicorsuperstitiousdenotationslikereligiosa,serpentinaetc.

15. PRINCIPLE OF PRIORITY
(i)Eachfamilyortaxonoflowerrankwithaparticularcircumscription,
positionandrankcanbearonlyonecorrectname(Art.11).(ii)Foranytaxon
fromfamilytogenuscomprehensive,thecorrectnameistheearliestrightful
one,validlypublishedwiththesamerank(Art.11).(iii)Anameofataxonhas
nostatusunderthiscodeunlessitisavalidlypublished(Art.12).(iv)The
applicationofbothconservedandrejectednamesisdeterminedby
nomenclaturaltype(Art.14).(v)“Whenanameproposedforconservationhas
beenprovisionallyapprovedbythegeneralcommittee,botanistsareauthorized
toretainitpendingthedecisionofalaterInternationalBotanicalCongress”.
ValidPublicationofnamesisusuallyconsideredbeginninginMay1753,the
dateofpublicationofSpeciesplantarumvol.IbyLinnaeus.Theprinciplethat
superiorityisfixedbythedateofvalidpublicationisknownasPrincipleof

16. PRINCIPLE OF PRIORITY
i.CorrectnameofthespeciesNymphaeanouchaliBurm.F.,1768.otherthree
namesofthegenusNymphaeaare
Nymphaeamalabarica.,1798
N.stellateWilld.,1799
N.acutiloba.,1824
ii.CorrectnameforZeaisselectedasperruleofpriority
ZeamaysL.,1753
Z.curaguaMolina,1782
Z,japonicavonHoutte,1886
Z.indurataSturter.,1885

17. PRINCIPLE OF PRIORITY
3.Whentwoormorenamesappearsimultaneouslyforaspecies,boththe
namesarecombined,thefirstauthortotakethenamingprocess.Thegeneric
nameTheaL.andCamelliaL.arepublishedsimultaneouslyon01.05.1753.In
1818,SweetcombinedandthegenusgetthenameCamellia.HetreatedThewa
assynonym.
LIMITATIONTOTHEPRINCIPLEOFPRIORITY
1.TheprincipleofprioritycametoexistenceafterpublicationofSpecies
plantarumofLinnaeusin01.05.1753.Thisiscalledstartingdate.Otherplant
groupsincludingseedplants,pteridophytes,Sphagnaceae,Hepaticae,most
Algae,andFungi,Slimemouldsandlichenswerepublishedin01.05.1753,
Mosseson01.01.1801,Fungion31.12.1801,Fossils31.12.1820.The
publicationbeforedatesforspeciesgroupareomitted.Startingdatesfor
supragenericnameswassetaViennaCongresson04.08.1789.

18. PRINCIPLE OF PRIORITY
2.Theprincipleofpriorityisappliedonlyuptofamilylevel.
3.Acorrectnameforataxonischosenconsideringnamesandepithets
availableatthatrank.Otherwise,asuitablenameisselectedtakingepithet
fromanotherrank.
4.Nominaconservandaaretobeusedascorrectnamesreplacingtheearlier
legitimatenames,earlierlegitimatenameisrejectedtreatedasnominarejicinda.
ThefamilynameTheaceaeD.Don,1825isconservedinplaceof
TernstromiaceaeMirbe,1813.ThegenusSesbaniaScop.,1777isconservedin
placeofSesbanAdans.,1763andAgatiAdan.,1763.
Thus,theabovelimitationsareconsideredasfarastheconservationofthe
namesatthedifferentrankandcategories.

19. TYPIFICATION/TYPE METHOD
Typificationisamethodologybywhichacertainrepresentativeofthegroupis
thesourceofthenameforthesamegroup.Thisiscallednomenclaturaltype.A
typeofaparticulargenusisaspeciessoastoaparticularfamilyisagenus.
TypeofaparticulargenusisspeciesasPoapratensisforPoa.Asingletype
specimenisdesignatedanditisgenerallytreatedasHolotype.Theholotype
shouldbekeptinapermanentherbariumandconservedproperly.Publication
onorafterJanuary1,12958ofthenameofanewtaxonoftherankofthegenus
orbelowisvalidwhenthesametypenameisindicatedPublicationofnameof
anewtaxonofgenusorbelowafterJanuary1,1990shouldcarryeitherthe
word‘typus’or‘holotypus’.PublicationofnamesonorafterJanuary1,2007
requiresaspecimenasatypebutincaseofmicroscopicalgaeandfungiwhere
preservationofthespecimenistechnicallydifficult,illustrationisacceptedas
type.

20. TYPIFICATION/TYPE METHOD
ICN’ssecondprinciplestatesthataspecimenmustbeassociatedwiththe
scientificnameknownasnomenclaturaltype.Anomenclaturaltypeiseithera
specimenormaybeanillustration.Example:Herbariumsheetforvascular
plants.Therearedifferentnomenclaturaltypes.
Holotype:Aspecimenorillustrationoriginallycitedbytheauthorin
protologue.Itisadefinitivereferencesourceforidentity.Citationofholotype
andsubmissionofitisoneofthecriteriaforvalidpublicationofabotanical
name.
Isotype:Duplicatespecimenoftheholotypecollectedfromsamepopulation
bysamepersononsamedatewithsamefieldnumber.Theyarethereliable
duplicatesofholotypeandmaybedistributedtovariousherbariaofvarious
regions.
Lectotype: Specimen selected fromoriginal material serves as a type, when no
holotype was designated at the time of publications or if holotype is missing or
destroyed.
Syntype:When more than one specimencited by the author in the protologue
without designating holotype.

21. TYPIFICATION/TYPE METHOD
Neotype:Specimenderivedfromnon-originalcollectionselected
asthetype,whenoriginalspecimenismissingordestroyed.
Paratype:Specimencitedintheprotologueisotherthan
holotype,isotypeorsyntype.
Epitype:Specimenorillustrationservesasaninterpretivetype,
whenholotype,neotypeorlectotypeisambiguous.
Thus, the type concept is the most important issue that to be
addressed in case of the developing the different type of
taxonomic problems. The different rules and regulations as framed
by ICBN is very important in this regard. Thus, addressing a
taxonomic problem with the adiof the element is very essential in
this regard.

22. REJECTION OF NAMES
Illegitimatenamesarenotacceptedbecausetheydonotobeyany
botanicalnomenclature.Alegitimatenameisalsonotrejectedanditis
rejectedduetothefollowingreasonsasmentionedbelow:
1.Tautonym-Whenthegenericnameandthespecificepithetaresame,
itiscalledtautonym.Inbotanicalnomenclature,tautonymiscompletely
notinunuseSometimes,naminginvolvestautonywhichisacceptedas
Sesbaniaseshan.Repetitionofaspecificepithetinanintraspecific
epithetdoesnotconstitutealegitimateautonym(Acacianiloticassp.
nilotica).
2.Nomennudum(nom.nud):Ataxonwithoutassociationofproper
descriptioniscallednom.nud.In1812,Wallichpublishedmanynames
withoutproperdescriptioninhiscataloguesinWall.calandthosewere
nomennudum.Butifthesamespeciesnamedproperlybyanother
author,thenewnamesremainvalid.Forexample,Quercusdilatata
wall.,nom.nud,butrejectedandreplacedbyQuercushimalayan
Bahadur,1972.

23. REJECTION OF NAMES
3.LainDiagnosis-Thescientificnameissubjecttorejectionwhenitisnot
effectivelypublished,notformulated,lackingtypificationandthediagnosisof
theelementwithoutinLatinlanguage.
4.Laterisonym-sometimesbycoincidence,twosamenames,basedonsametypes
comeindependentlyatdifferenttimesbydifferentauthors,thenameofthe
earlierauthorstandsamongthe‘Isonymes’.Thenameispublishedwiththe
originalplaceofvalidpublication.Baker(1992)andChristensen(1905)
independentlypublishedthetaxon,AlsophilakalbrengeriasasubstituteofA.
podophyllaBaker(19812).A.kalbrengeriisbeingalaterisonym,isrejected.
5.Nomensuperfluum(nom.superfl.)-Asuperficialpublishednamebecomes
illegitimateanditmustberejected.Itindicatesthatthenameisoutoftherule
ofthecode.In11790,PhyskiumnastasLour.,wastransferredtothegenus
Vallisneriawithoutnatus.In1826,deJessieunameditVallisneriaphysakium
Juss.,thatbecomessuperfluous.Subsequently,thespeciesin1974wasproperly
namedasVallisnerianatas(Lour.)Hara.

24. REJECTION OF NAMES
6.Nomenambiguum(nom.ambig.)-sometimesanameisusedbythedifferent
authorsindifferentsense,andapersistenterrorisproduced,thenameissubject
torejection.Asanexample,RosavillosaL.isasourceerrorduetoitsusefor
differentspecies.Hence,itisrejected.
7.Nomenconfusum(nom.confus.)-Inthiscase,itbecomesdifficulttoselecta
satisfactorylectotypeamongtwoormoreconflictingspecies.Forexample,in
thegenusActinotinusthecharactersarederivedfromtwogeneraViburnumand
Asculuswheretheinsertionofinflorescenceintheformerandtheterminalbud
latter.,So,thenameAconitusforthetaxonwasabandoned.
8.Nomendubium(nom.dub.)-Whentheplacementofataxonisdoubtfulto
whichitshouldbepublished,thenameofthetaxonisrejected.In1753,
LinnaeusnamedRhinanthuscrista-galliLforagroupofseveralvarietiesand
subsequentlyherejectedhisownconceptandusedseparatenamesforthe
varietiesdiscardingR.crista-galli.Thoughthenamecontinuedforconsiderable
periodbyauthors,finallyin1939Schwarztreatedundernomen.dubium.

25. NAME OF THE HYBRIDS
Hybridsplantsmaybecrossbetweenthetwoelementsatthe
differentlevel.Itmaybeeithernothogenusandnothospecies.The
hybridbetweenthetwospeciesisexpressedbyputtingacross
betweenthespeciesisexpressedbyputtingacrossbetweenthe
specieswhichiscalledhybridformulaasstatedbelow.
i.SalixauritaXS.caprea
ii.AgrostisXPolypogon
iii.AgrostisstoloniferaXPolypogonmonspeliensis.
Therearesomerulesshowingthepositionofthespeciesina
hybridformula.
Speciesinaformulaputinalphabeticalorder,
GenerallyFemaleiskeptfirstusingspecificsigntodenoteit.
Ifthesequenceisnotfollowed,reasonmustbeacknowledged.

26. NAME OF THE HYBRIDS
Hybridmaybeinterspecificofintergeneric,interspecificinvolves
twospeciesundersamegenusbutintergenericinvolvestwo
differentgenera.Abinarynameisassignedtotheinterspecfic
hybridornotho-speciesputtingXbeforethespecificepithet.The
hybridshouldbeself-perpetuatingandorreproductivelyisolated.
Thefollowingexamplescanbeautifytheevent.
i.RosaXodorata(Interspecific)derivedfromRosachinensisX
R.gigantea.
ii.SalixXcapreola(Interspecific)derivedfromSalixauritaand
Salixcaprea.
Thevariantsofinterspecifichybridsarenamedasnothosubspecies
andnothovarities,e.g.Salixrubensnothovar.basfordiana.

27. NAME OF THE HYBRIDS
Inintergenericcross,thenamingofthehybridfollowsthefollowingrulesas
statedbelow:
i.AcrossbetweenTriticum&Secalethatproducesaintergenerichybrid,
namedasxTriticosecaleandincaseofxAndropogonitisAgrostisxPolypogon
andinxPaeoniafromPyrusandCynodon.
Thenameofthenothogenusderivedfromthecombinationofthetwo.
Sometimes,intergenericnamingincludesfourormoregeneratoproducean
intergenerichybrid.Thehybridcarriesacrosssignimmediatelybeforeitandit
shouldbemorethaneightsyllables.ThecondensedformulaxPotinaraisthe
outcomeof4genera-BrassavolaxCattleyaxLaeliaxSophrontitis.Thehybrid
genusendwith–araderivedfromthepersonwhoproducedthehybridorso.

28. NAME OF THE HYBRIDS
Whenthenothogeneicnameisformedoutofthreegenera,thenamedoesnot
containeightsyllables.Butitconsistsofwholeorfirstpartofonefollowedby
thewhole,oranypartofthesecondfollowedbythewholeorthelastpartofthe
thirdfollowedbytheoneormoreconnectingvowels.Thenothogenicnameof
thetrigenichybridmaybenamedastetragenichybridiftheabovepatternisnot
acceptedi.e.frompersonalnametowhichaddedthetermination–ara.
Nothogenichybridof3genera:
Xsopholaeliocattleyaya,itisderivedfrom(xSophronitisxLaeliaxCattleya).
Twospeciesinvolvedingraftaredemarcatedbyplussign,e.g.Hibiscusrosa-
sinensis+andH.syricus+---

29. THANK YOU VERY MUCH
References:
1.A text Book of Plant Systematics-C. Mohanty
2.A text Book of Botany-Hait, Bhattacharya & Ghosh
3. Plant taxonomy-O.P. Sharma,
4. Advanced Plant Taxonomy-A.K. Mondal
5.Studies in Botany-Mitra, Guha& Choudhury
6.College Botany-Kar& Ganguly
7.Google for Images,
8.Different websites for reference reading sources.
Disclaimer: This PPT has been designed and developed for enriching the free
knowledge domain in the field of plant scienceswithout keeping any financial
interest.

30. THANK YOU FOR YOUR JOURNEY