Principles and Rules.pdf

This PPT has the pleasure to bring a bird's eye view of the rules and principles used in 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. ICN OR ICBN
Linnaeusin1737&1751proposedtheelementaryrulesof
namingplantsin‘PhilosophiaBotanica’.Thenin1813,A.P.de
Candollesetforthadetailedrulesregardingplants
nomenclatureinhisTheorieselementiredelabotanique.The
samerulesofLinnaeus,A.P.deCandolleandhisson,Alphonse
deCandollewerelaterevolvedintoourpresentInternational
CodeofBotanicalNomenclature(ICBN).
AlphonsedeCandolleconvenedthefirstInternational
BotanicalCongressin1867inPariscalledParisCodeattended
bybotanistsfromseveralcountries.Theyadoptedasetofrules
ofplantnomenclature,mostofwhichwereproposedbyA.de
Candolle.SubsequentmeetingsofICBNheldin1892
(Rochestercode),1905(ViennaCode),1907(AmericanCode)
andageneralagreementcameintotheforceonIBCat

3. IBC CHRONOLOGY
Cambridge(1930)-”forthefirsttimeinbotanicalhistory,acodeof
nomenclaturecameintobeingthatwasinternationalinfunctionas
wellasinname”.ThisiscalledICBN.Thenfrom1930,anumberof
IBCarebeingheldasperorderfortheadoptionofrulesand
recommendationsinPlantstaxonomy.
1935-Amsterdam
1850-Stochholm
1954-Paris
1959-Montreal
1964-Edinburgh
1969-Seattle
1975-Leningrad
1981-Sydney
1987-Berlin

4. IBC CHRONOLOGY
1993-Tokyo,1999-St.Louis,2005-Vienna2011-Melbourne
2017-Snenzhen,2024-Madrid
TheIBChasthepowertoaltertheICN(InternationalCodeof
Nomenclatureforalgae,fungi,andplants,whichwasrenamed
fromtheInternationalCodeofBotanicalNomenclature(ICBN)
attheXVIIIIBC.FormallythepowerresideswiththePlenary
Session;inpracticethisapprovesthedecisionsofthe
NomenclatureSection.TheNomenclatureSectionmeets
beforetheactualCongressanddealswithallproposalsto
modifytheCode:thisincludesratifyingrecommendations
fromsub-committeesonconservation.Toreducetheriskofa
hastydecisiontheNomenclatureSectionadoptsa60%
majorityrequirementforanychangenotalreadyrecommended
byacommittee

5. PRINCIPLES
I.Botanicalnomenclatureisindependentofzoological
nomenclature.Thecodeappliesequallytonamesoftaxonomic
groupstreatedasplantswhetherornotthesegroupswere
originallysotreated(PlantsdonotincludeBacteria).
II.Applicationofnamesoftaxonomicgroupsisdeterminedby
meansofnomenclaturetypes.
III.Thenomenclatureofataxonomicgroupisbasedupon
priorityofpublication.
IV.Eachtaxonomicgroupwithaparticularcircumscription,
position,androutecanbearonlyonecorrectname,theearliest
thatisinaccordancewiththerules,exceptinspecificcases.
V.ScientificnamesoftaxonomicgroupsaretreatedasLatin
regardlessoftheirderivation.
VI.Therulesofnomenclatureareretroactiveunlessexpressly
limited.

6. PRINCIPLES OF ICBN

7. RULES OF NAMING PLANTS
1)Accordingtobinomialsystemnameofanyplantspecies
consist of two names.
ForE.g.:Solanumtuberosum(botanicalnameofPotato)
Thefirstnameshowgenericname&secondnameshow
specific name.
Both names should not be same.
2)Lengthofgenericnameandspecificnameshouldnotbe
lessthanthreelettersandmorethantwoletters.
3)Firstletterofgenericnameshouldbeincapitalletter&
specificnameshouldbeinsmallletter.
4)Whenwrittenthesenamestheyshouldbeunderlinedbut
duringthetimeofprinting,theyshouldbeitalic.
5)Nameofthescientistshouldbewritteninshortletter
after the specific name.
6)ScientificnameshouldbederivedfromLatinorGreek
language.

8. RULES AND RECOMMENDATIONS OF ICBN
AccordingtotheICBN(1983),thecode“aredividedinto
Rules,setoutinArticles,andRecommendations”.Asmention
underpointNo.4ofthePreambleof1983ICBN”Theobject
oftheRulesistoputthenomenclatureofthepastintoorder
andtoprovideforthatofthefuture,namescontrarytoarule
cannotbemaintained”.
TherulesandrecommendationsofICBNapplytoall
organismstreatedasplants(includingfungibutexcluding
bacteria),whetherfossilornon-fossil.Nomenclatureof
bacteriaisgovernedbyaseparatecodecalledInternational
CodeofBacterialNomenclature(ICNB)andsoasto
cultivatedplantsbyICNCP.
ItisstatedunderpointNo.10ofICBNthatthelatest“edition
oftheCodesupercodesallpreviouseditions”

9. 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.

10. 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

11. RANK AT THE LEVEL OF GENUS & SPECIES
Asperpreviousinformationisconcernedabouttheendingsofthe
rankofthetaxa,differentsuffixesareusedtodesignatethem.The
questionariseshowthenameofthegenusandspeciesare
designedandwhetherdotheyfollowanystrictruleinthisregard
fornamingthem?Theanswerliesintheunderstandingofthe
genusandspeciesnamedeterminedasstatedbelow:
A.Genericname:
i.Commemorationofaperson-Thenamesmaybededicatedto
greatpersonalitiesindifferentfieldsasstatedbelow:
BauhiniafromBauhin,DarwiniafromDarwin,Victoriafromthe
QueenVictoriaofEngland,WashingtoniafromGeorge
Washington.Whenthenamesareusedforgenus,ittakesfamine
formandsomerulesarefollowedinthisregard.LikeOtto
becomesOttoetc.

12. 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

13. SPECIES NAME
Alltheepithetusuallystartswithsmallletteranditmayderive
fromanyorcompoundarbitrarily.
Nameofaperson:WallachiafromWallchi,HookariforHooker
etc(Ifitisbecomesgenitiveorpossessiveform,itbecomes
capital).
Formedbyaplace-indicafromIndia,kasmiriansisfromKashmir,
etc.
Basedoncharacter-albaoralbusoralbumforwhite,cultivated
speciesassativa,cordifoliaforcordateleaves.
Nouninapposition-Someepithetsmayhavetheirowngenderas
theyarenouninapposition,innominativecase.Pyrusmalusis
basedonGreeknamemalusforcommonpeople.
Someotherspecificepithetsarerara(rare),vulgaris(common),
autmnalis(autumn),ethnicorsuperstitiousdenotationslike
religiosa,serpentinaetc.

14. PRINCIPLE OF PRIORITY
(i)Eachfamilyortaxonoflowerrankwithaparticular
circumscription,positionandrankcanbearonlyonecorrectname
(Art.11).(ii)Foranytaxonfromfamilytogenuscomprehensive,
thecorrectnameistheearliestrightfulone,validlypublishedwith
thesamerank(Art.11).(iii)Anameofataxonhasnostatusunder
thiscodeunlessitisavalidlypublished(Art.12).(iv)The
applicationofbothconservedandrejectednamesisdeterminedby
nomenclaturaltype(Art.14).(v)“Whenanameproposedfor
conservationhasbeenprovisionallyapprovedbythegeneral
committee,botanistsareauthorizedtoretainitpendingthe
decisionofalaterInternationalBotanicalCongress”.Valid
PublicationofnamesisusuallyconsideredbeginninginMay
1753,thedateofpublicationofSpeciesplantarumvol.Iby
Linnaeus.Theprinciplethatsuperiorityisfixedbythedateof
validpublicationisknownasPrincipleof

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

16. PRINCIPLE OF PRIORITY
3.Whentwoormorenamesappearsimultaneouslyforaspecies,
boththenamesarecombined,thefirstauthortotakethenaming
process.ThegenericnameTheaL.andCamelliaL.arepublished
simultaneouslyon01.05.1753.In1818,Sweetcombinedandthe
genusgetthenameCamellia.HetreatedThewaassynonym.
LIMITATIONTOTHEPRINCIPLEOFPRIORITY
1.Theprincipleofprioritycametoexistenceafterpublicationof
SpeciesplantarumofLinnaeusin01.05.1753.Thisiscalled
startingdate.Otherplantgroupsincludingseedplants,
pteridophytes,Sphagnaceae,Hepaticae,mostAlgae,andFungi,
Slimemouldsandlichenswerepublishedin01.05.1753,Mosses
on01.01.1801,Fungion31.12.1801,Fossils31.12.1820.The
publicationbeforedatesforspeciesgroupareomitted.Starting
datesforsupragenericnameswassetaViennaCongresson
04.08.1789.

17. PRINCIPLE OF PRIORITY
2.Theprincipleofpriorityisappliedonlyuptofamilylevel.
3.Acorrectnameforataxonischosenconsideringnamesand
epithetsavailableatthatrank.Otherwise,asuitablenameis
selectedtakingepithetfromanotherrank.
4.Nominaconservandaaretobeusedascorrectnamesreplacing
theearlierlegitimatenames,earlierlegitimatenameisrejected
treatedasnominarejicinda.ThefamilynameTheaceaeD.Don,
1825isconservedinplaceofTernstromiaceaeMirbe,1813.The
genusSesbaniaScop.,1777isconservedinplaceofSesban
Adans.,1763andAgatiAdan.,1763.
Thus,theabovelimitationsareconsideredasfarasthe
conservationofthenamesatthedifferentrankandcategories.

18. TYPIFICATION/TYPE METHOD
Typificationisamethodologybywhichacertainrepresentativeofthe
groupisthesourceofthenameforthesamegroup.Thisiscalled
nomenclaturaltype.Atypeofaparticulargenusisaspeciessoastoa
particularfamilyisagenus.TypeofaparticulargenusisspeciesasPoa
pratensisforPoa.Asingletypespecimenisdesignatedanditis
generallytreatedasHolotype.Theholotypeshouldbekeptina
permanentherbariumandconservedproperly.Publicationonorafter
January1,12958ofthenameofanewtaxonoftherankofthegenusor
belowisvalidwhenthesametypenameisindicatedPublicationof
nameofanewtaxonofgenusorbelowafterJanuary1,1990should
carryeithertheword‘typus’or‘holotypus’.Publicationofnamesonor
afterJanuary1,2007requiresaspecimenasatypebutincaseof
microscopicalgaeandfungiwherepreservationofthespecimenis
technicallydifficult,illustrationisacceptedastype.

19. TYPIFICATION/TYPE METHOD
ICN’ssecondprinciplestatesthataspecimenmustbeassociatedwith
thescientificnameknownasnomenclaturaltype.Anomenclatural
typeiseitheraspecimenormaybeanillustration.Example:Herbarium
sheetforvascularplants.Therearedifferentnomenclaturaltypes.
Holotype:Aspecimenorillustrationoriginallycitedbytheauthorin
protologue.Itisadefinitivereferencesourceforidentity.Citationof
holotypeandsubmissionofitisoneofthecriteriaforvalidpublication
ofabotanicalname.
Isotype:Duplicatespecimenoftheholotypecollectedfromsame
populationbysamepersononsamedatewithsamefieldnumber.They
arethereliableduplicatesofholotypeandmaybedistributedtovarious
herbariaofvariousregions.
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.

20. 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.

21. 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.

22. REJECTION OF NAMES
3.LainDiagnosis-Thescientificnameissubjecttorejectionwhenitisnot
effectivelypublished,notformulated,lackingtypificationandthe
diagnosisoftheelementwithoutinLatinlanguage.
4.Laterisonym-sometimesbycoincidence,twosamenames,basedon
sametypescomeindependentlyatdifferenttimesbydifferentauthors,
thenameoftheearlierauthorstandsamongthe‘Isonymes’.Thenameis
publishedwiththeoriginalplaceofvalidpublication.Baker(1992)and
Christensen(1905)independentlypublishedthetaxon,Alsophila
kalbrengeriasasubstituteofA.podophyllaBaker(19812).A.
kalbrengeriisbeingalaterisonym,isrejected.
5.Nomensuperfluum(nom.superfl.)-Asuperficialpublishedname
becomesillegitimateanditmustberejected.Itindicatesthatthenameis
outoftheruleofthecode.In11790,PhyskiumnastasLour.,was
transferredtothegenusVallisneriawithoutnatus.In1826,deJessieu
nameditVallisneriaphysakiumJuss.,thatbecomessuperfluous.
Subsequently,thespeciesin1974wasproperlynamedasVallisneria
natas(Lour.)Hara.

23. REJECTION OF NAMES
6.Nomenambiguum(nom.ambig.)-sometimesanameisusedbythe
differentauthorsindifferentsense,andapersistenterrorisproduced,
thenameissubjecttorejection.Asanexample,RosavillosaL.isa
sourceerrorduetoitsusefordifferentspecies.Hence,itisrejected.
7.Nomenconfusum(nom.confus.)-Inthiscase,itbecomesdifficultto
selectasatisfactorylectotypeamongtwoormoreconflictingspecies.
Forexample,inthegenusActinotinusthecharactersarederivedfrom
twogeneraViburnumandAsculuswheretheinsertionofinflorescence
intheformerandtheterminalbudlatter.,So,thenameAconitusforthe
taxonwasabandoned.
8.Nomendubium(nom.dub.)-Whentheplacementofataxonis
doubtfultowhichitshouldbepublished,thenameofthetaxonis
rejected.In1753,LinnaeusnamedRhinanthuscrista-galliLforagroup
ofseveralvarietiesandsubsequentlyherejectedhisownconceptand
usedseparatenamesforthevarietiesdiscardingR.crista-galli.Though
thenamecontinuedforconsiderableperiodbyauthors,finallyin1939
Schwarztreatedundernomen.dubium.

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

25. 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.

26. NAME OF THE HYBRIDS
Inintergenericcross,thenamingofthehybridfollowsthe
followingrulesasstatedbelow:
i.AcrossbetweenTriticum&Secalethatproducesaintergeneric
hybrid,namedasxTriticosecaleandincaseofxAndropogonitis
AgrostisxPolypogonandinxPaeoniafromPyrusandCynodon.
Thenameofthenothogenusderivedfromthecombinationofthe
two.
Sometimes,intergenericnamingincludesfourormoregenerato
produceanintergenerichybrid.Thehybridcarriesacrosssign
immediatelybeforeitanditshouldbemorethaneightsyllables.
ThecondensedformulaxPotinaraistheoutcomeof4genera-
BrassavolaxCattleyaxLaeliaxSophrontitis.Thehybridgenus
endwith–araderivedfromthepersonwhoproducedthehybrid
orso.

27. NAME OF THE HYBRIDS
Whenthenothogeneicnameisformedoutofthreegenera,the
namedoesnotcontaineightsyllables.Butitconsistsofwholeor
firstpartofonefollowedbythewhole,oranypartofthesecond
followedbythewholeorthelastpartofthethirdfollowedbythe
oneormoreconnectingvowels.Thenothogenicnameofthe
trigenichybridmaybenamedastetragenichybridiftheabove
patternisnotacceptedi.e.frompersonalnametowhichaddedthe
termination–ara.
Nothogenichybridof3genera:
Xsopholaeliocattleyaya,itisderivedfrom(xSophronitisxLaeliax
Cattleya).
Twospeciesinvolvedingraftaredemarcatedbyplussign,e.g.
Hibiscusrosa-sinensis+andH.syricus+---

28. 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,
Studies in Botany
College Botany
Google for Images
Different websites
Disclaimer: this PPT has been designed and developed for
enriching the free knowledge domain in the field of plant sciences.