ICBN CLARIFICATION NEEDED: USE OF RANKS

2005·3.1 MB·English

by  Guy L Nesom

ICBNCLARIFICATIONNEEDED:USEOFRANKS
GuyL.Nesomand BarneyLipscomb
BotanicalResearchInstituteofTexas
509PecanStreet
FortWorth,Texas76102-4060,U.S.A.
ABSTRACT
Thecurrent(2000)InternationalCodeofBotanicalNomenclatureisopentodivergentinterpreta-
tionregardingtheuseofrani<s.Article4.1outlmessecondaryrankstobeusedbetweentheprincipal
ranksoffamilyandspeciesandbelowspecies.Article4.2statesthatranksprefixedby"sub"(termed
hereas"tertiary"rank,immediatelysubsidiaryinsequenceandrelativeordertoprincipalorsecond-
aryranks)areusedtoincreasethenumberofrankstoa"greaternumber"thanformedin4.f.Some
taxonomists,incontrast,apparentlyinterprettheseArticlessuchthattertiaryranksmaybeused
withoutreferencetosecondaryranks(e.g.,subgenusmagenuswithoutsectionsorseries;subspecies
inspecieswithoutvarietiesorforms).AlternateformulationsareofferedforArticles4and5that
maymoreclearlyexpresstheintentoftheCode:Formulation1iftheintentistomandatethat
tertiaryranksbetweenfamilyandspecies,andbelowspecies,beusedonlyinconjunctionwithsec-
ondaryranks;Formulation2iftheintentisthattertiaryranksmaybeusedwithoutreferenceto
secondaryranks.
RESUMEN
ElactualCodigoInternacionaldcNomenclaturaBotanica(2000)estaabiertoamterpretaciones
diversasrespectoalusodelosrangos.ElArticulo4.1esbozalosrangessecundariosparausarentre
losrangosprincipalesdefamiliayespecie,yespecieeinfenores.ElArticulo4.2establecequelos
rangosconelprefijo"sub-"(Uamadosaquirango"terciario",inmediatamentesiguientesensecuencia
yordenrelativealosrangosprincipalesosecundarios)seusanparaincrementarelmimeroderangos
aun"numeromasgrande"quelosformadosen4.1.Algunostaxonomos,porelcontrano,interpretan
aparentementeestosArticulosdemodoquelosrangosterciariospuedenusarsesinreferenciaalos
rangossecundarios(ej.subgeneroenungenerosinseccionesoseries;subespeciesenespeciessin
variedadesoformas).SeofreceniormulacionesalternativasparalosArticulos4y5quepueden
expresarmasclaramentelaintenciondelCodigo:Eormulacion1silaintencionesdeexigirquelos
rangosterciariosentrefamiliayespecie,ypordebajodeespecie,seusensoloenconjuncionconrangos
secundarios;FormulaciOn2silaintencionesquelosrangosterciariospuedanusarsesinreferenciaa
losrangossecundarios.
TheArticlesoftheInternationalCodeofBotanicalNomenclature(Greuteret
al.2000,the"SaintLouisCode")are"mandatory"rules(Preface,p.vii),andthey
aregenerallycarefullyandrigorouslyfollowedbytaxonomicbotanists.Such
nomenclaturalprescriptionsareintendedtoprovideastablemethodofnam-
ingandtoavoidcreationofsuperfluousnames.Validpublicationmustbein
accordancewiththeArticles.
The2000Codeisopentodivergentinterpretationregardingtheuseof
ranksandassociatedimplicationsforvalidnomenclaturalpractice.AsArticles
4.1and4.2arewritten,ranksm4.2(i.e.,ranksinadditiontothosein3.1and4.1)
SI0A21{4):2185-2191.2005
2186 BRIT.ORG/SIDA21(4)
areusedinaclassificationafterassociatedranksin3.1and4.1areused,i.e.,ranl<
subgenusisusedinagenusaftertlierearenamedsectionsand/orseriesinthe
classification;similarly,ranksubspeciesisusedinaspeciesinwhichvarieties
and/or[ormsalreadyaremuse.Currentpractice,however,isinconsistentre-
gardingwhichranksmustbeusedandwhichranksareoptional.Weplacethe
followingobservationsandsuggestionsonrecordwiththehopethattheymay
leadtoclarilicationo(thispartoftheCode.
Rulespertainingtosequenceandrelativeorderofranksarefoundprima-
rilyinArticles3,4,and5.Acloselyrelatedpairoftheserules—Articles4.1and
4.2—isthefocalpointofapparentambiguity.
Article4.1/^Thcsecondaryranksoftaxaindeiccndingsequcncearetribe(trihus)
betweenjamilyandgenus,section(sectio)andseries(series)betweengenusand
species,andvariety(varietas)andform(forma)belowspecies."
Article4.2.''Ijagreaternumberofranksoflaxaisdesired,thetermsjortheseare
madebyaddingtheprefixsub-tothetermsdenotingtheprincipalorsecondary
ranks.Aplantmaythusbeassignedtotaxaofthefollowingranks(indescending
sequence):regnum,snhregnum,divisioorphylunrsuhdivisioorsu.hphylum,classis,
suhclassis,ordo,suhordojamilia,suhfamilia,tribus,suhtrihus,genus,subgenus,
sectio,suhsectio,series,subscrie,s,species,subspecies,varietas,svbvarietas,forma,
suhforma."[boldadded]
Article4.1outlinessecondaryrankstobeusedbelowprincipalranks.Article
4.2statesthatranksprefixedby"sub"andimmediatelysubsidiaryinsequence
toprincipalorsecondaryranksareusedtoincreasethenumberofranks(pre-
sumablyfora"greaternumber"thanformedin4.1).
Recommendation26A.2appearstobeconsistentwiththeintentoftheICBN
inusingthe"sub"ranksinconjunctionwithranksprovidedin3.1and4.1:
Recommendation26A.2"Asubspeciesnotmcludingthetypeojthecorrectnameof
thespeciesshould,wherethereisnoobstacleundertherules,hegivenanamewith
ihesameIi)]alepithetandtypeasanameofoneofitssubordinatevarieties."
Article3specifiestheprincipalranks"indescendingsequence"asking-
dom,divisionorphylum,class,order,familygenus,andspecies.Articles4.1
and4.2dealwithsecondaryranks(4.1)and"tertiaryranks"(4.2—thosepre-
fixedby"sub;"althoughthephrase"tertiaryrank"isnotusedbytheICBN,itis
ausefuloneandapparentlyconsistentwiththeintentoftheCode).Article5.1
emphaticallyfixestherelativeorderofranks.
Article5.1."ThelelaliveorderoftheranksspecifiedinArt.3and4mustnotbe
aherediseeArt.33.7and33.8)."
Examplesinclarificationin33.7indicatethat
1)principalranksmustbeassignedinrelativeorder(e.g.,speciesmaynotcon-
taingenera);
NESOMANDLIPSCOMB,KBNCLARIFICATION:USEOFRANKS 2187
2)secondaryranksmustbeusedwithintheprincipalranktowhichtheyare
subsidiary(e.g.,sectionmustbeusedwithintherankofgenus);and
3)asecondaryrankcanbesubsidiaryonlytoasecondaryrankearlierinrela-
tiveorder(e.g.,formscannotbedividedintovarieties).
Basedonthe4.2sequenceandrelativeorderofranks,althoughnotexplicitly
giveninexamplebytheCode,varietiescannotbedividedintosubspecies.Va-
rietiescanbeclusteredwithinsubspeciesrank.
Changesinstitutedinthe1994Code
ThestructureofArticles4.1and4.2mthe2000(SamtLouis)Codewasfirst
institutedmthe1994("Tokyo")Code(Greuteretal.1994),whichdividedAr-
ticle4.1ofthe1988Code(Greuteretal.1988)intotwoparts(4.1and4.2).The
newlystructuredArticles4.1and4.2remamedunchangedinthe2000Code
andwerenotsuggestedformodificationbytheViennabotanicalcongressfor
theforthcoming2006Code(FredBarrie,pers.comm.).The1988Codehasthe
following:
Article3.1."Theprincipalranksoftaxainascendingsequenceare:species(spe-
cies),genus(genus),family(familia),order(ordo),class(c/t;.s.si.s),division
(divisio),andkingdom(regnum).Thus,exceptforsomefossilplants(seeArt.
3.2),eachspeciesisassignabletoagenus,eachgenustoafamilyetc."
Article4.1."Ifagreaternumberofranksoftaxaisrequired,thetermsforthese
aremadeeitherbyaddingtheprefixsub-tothetermsdenotingtheranksorby
theintroductionofsupplementaryterms.Aplantmaythusbyassignedtotaxa
ofthefollowingranks(indescendingsequence):regnum,suhrcgnum,divisio,
suhdivisio,dassis,subclassis,ordo,suhordo,[amilia,suhfamilia,tribus,suhtribus,
genus,subgenus,sectio,subseciio,scries,subseries,species,subspecies,varielas,
subvarietas,Jorma,subjorma."
Nodistinctioninthe1988Codewasmadeamongranksbelowprincipal
ranks.Thephrase"secondaryranks"(relerredtomthe1988Codeas"supplemen-
taryterms")wasfirstintroducedinthe1994Code.Thetwoproposalsforchange
relatingto1988Article4.1(Silva1993;Greuter&McNeill1993)wererejectedby
generalvote(McNeill1993)butwerereferredtotheEditorialCommittee,which
adoptedtheminslightlyinodifiedform(Greuter,McNeill,&Barrie1993).
IntheoriginalproposalbySilvaformodificationofArticle4.1(1993,p.
186),identificationofsecondaryrankswasdonewiththeintention,atleastin
part,that"proliferationofranksbyuseofaprefixshouldberestrictedto...prin-
cipalandsecondaryranks."Indiscussionoftheproposalsatthenomenclature
sessions(priortotheEditorialCommitteemeeting),Rapporteur-generalGreuter
notedthefollowing,regardingwhatwastobecomeArticle4.2:"WhatSilvahad
attempted,andperhapspartlyachieved,wastobringacoherentlogicintothe
hierarchyofranks—wherehierarchymeant,notthetaxonomichierarchybut
aclassificationofranksbytheirimportance"(Greuteretal.1993,p.40).
2188 BRIT.ORG/SIDA21(4)
DifferenceinInterpretationofthe2000Code
ThewordingofArticles41and4,2inthe2000Codedirectlyimpliesthatter-
tiaryranksareusedbetweenfamilyandgenus,betweengenusandspecies,and
belowspecies(secondaryranksareavailableineacharea)onlyafteruseofan
immediately precedingsecondaryrank(indescendingsequence).Between
kingdomandlamily(wheresecondaryranksdonotexist),tertiaryranksim-
mediatelyloUowprincipalranks.NoneoftheCodenotesorexamplesperti-
nentto4.1,4.2,or5.f(and33.7or33.8,aspointedtoby5.1),however,provides
explicitclarificationregardingthis,hialternativeinterpretationandinprac-
tice,andapparentlycontrarytothe2000Code,subfamiliesareusedinaclassi-
ticationwithoutuseoftribes,subgenerawithoutsections,andsubspecieswith-
outvarieties.
Thisdiflerenccininterpretationmayexistbecauseofadisparitybetween
Articles41and42:tertiaryranksprecedethesecondaryranksin"relativeor-
der"and"descendingsequence"butbecausetertiary'ranksareusedtoincrease
thenumberofranksbeyondthoseprovidedbysecondaryranks,secondaiy
ranksprecedetertiaryranksinorderofuse.litheCodedoesnotintendtoman-
datethisorderofuseinranks,thentheseparationof4.1from4.2,coupledwith
thewordingof 4.2("Ifagreaternumberofranksoftaxaisdesired"),isstated
incorrectlyoratleastismisleading.
Alternatelormulationsforclarification
Inclarilicationoftheproblemdiscussedhere,modificationsofthe2000(Saint
Louis)Codearcsuggested.Twoalternateformulationsprovideacontrastbe-
tweenwhatappeartobedifferentinterpretationsoftheCode.Article3.1(un-
modifiedfromthe2000code)isincludedwithinbothalternatives.
Ifmodilicationsarenecessaryforthe20f2ICBNmregardtopointscon-
sideredhere,aformalproposalinTaxonwillberequired.Becauseoftheexpanse
oftimebetweennowandthenextCodeversion,becausewearcnottakinga
positionol advocacy,andbecausewhattheEditorialCommitteeintendedin
1993isnotcleartous,weollerthiscommentaryasabeginningpointofdiscussion.
Formulation1
IftheintentofArticles4and5istomandatethattertiaryranksbeusedonlyin
conjunctionwithsecondaryranksbetweenfamilyandgenus,betweengenus
andspecies,andbelowspecies,thenwesuggestthatthefollowingbetterex-
presstheintentoftheCode.
Article3.1(unmodifiedfrom 2000code).Theprincipalranksoftaxain
descendingsequenceare:kingdom(regnum),divisionorphylum(divisio,pliy-
lum),class(classis),order(ordo),family(lamilia),genus(genus),andspecies
(species).Thus,eachspeciesisassignabletoagenus,eachgenustoafamily,etc.
Article 4.1.A plantmaybeassigned totaxaofthefollowingranks(in
NESOMANDLIPSCOMB,ICBNCLARIFICATION:USEOFRANKS 2189
descendingsequence):regnum,subregnum,divisioorphylum,subdivisioor
subphylum,classis,subclassis,ordo,subordo,familia,subfamilia,tribus,
subtribus,genus,subgenus,sectio,subsectio,series,subseries,species,subspe-
cies,varietas,subvarietas,forma,subtorma.
Article4.2.Secondaryranksoftaxaaretribe(tribus)betweenfamilyand
genus,section(sectio)andseries(series)betweengenusandspecies,andvari-
ety(varietas)andform(forma)belowspecies.Termsfortertiaryranksoftaxa
aremadebyaddingtheprefix"sub-"tothetermsdenotingtheprincipaland/
orsecondaryranks.Tertiaryranksareaddedifagreaternumberofranksof
taxa(beyondsecondaryranks)isdesired.
Article4.3.Furtherranksmayalsobeintercalatedoraddedifagreater
numberofranksoftaxa(beyondtertiaryranks)isdesired,providedthatconfu-
sionorerrorisnottherebyintroduced.
Article5.1.TherelativeorderoftheranksspecifiedinArts.3and4must
notbealtered(seeArt.33.7[theexamplesfollowing33.7wouldhebetterplaced
here]and33.8).Thesequenceofuseofranksbetweentheprincipalranksfam-
ilyandspeciesandbelowspeciesissecondary(indescendingsequence),then
tertiary.Tertiaryranksfollowtheprincipaland/orsecondaryranksfromwhich
theyarederived.Anyofthetertiaryranksmaybeomittedwithoutalteringthe
relativeorder;thesecondaryranksseriesandformamaybeomittedwithout
alteringtherelativeorder
Notea.—Useoftherankoftribeprecedesuseolsubfamily;useoftherank
ofsectionprecedesuseofsubgenusorseries;useoftherankofvarietypre-
cedesuseofsubspeciesorform.
Noteb.—Agenusmaybeincludedinafamilywithoutreferencetoatribe
ortoasubfamily(omissionofoneorbothoftheranksbetweengenusandfam-
ilydoesnotaffecttherelativeorderofranks).
IfFormulation1wereadopted,adatemightbesetbeyondwhichtherules
wouldapply—inordertoavoidchaoticinvalidityofnamesattertiaryrank.Or,
proposalofanameattertiaryrankpriortoanappropriatenameatsecondary
rankmightbesettoautomaticallyestablishthesecondaryrank.
Formulation2
IftheintentofArticles4and5isthattertiaryranksmaybeusedwithoutrefer-
encetosecondaryranks,thenwesuggestthatthefollowingbetterexpressthe
intentoftheCode.Thisformulationreturnstothelessrestrictivenatureofthe
1988Code,inwhichnodistinctioninusewasmadebetweensecondaryand
tertiaryranks(astheyaretermedhere).Flere,thereisnoproblemwithsubspe-
ciesassoleinfraspecificrankwithinaclassificationorwithsubgenusassole
subdivisionofagenus.
Article3.1(unmodifiedfrom2000code).Theprincipalranksoftaxain
descendingsequenceare:kingdom(regnum),divisionorphylum(divisio,
2190 BRIT.ORG/SIDA21(4)
phylum),class(classis),order(ordo),family(familia),genus(genus),andspecies
(species).Thus,eachspeciesisassignabletoagenus,eachgenustoatamily,etc.
Article4.1(sameasini-ormulatiok1).Aplantmaybeassignedtotaxaof
thelollowingranks(indescendingsequence):regnum,subregnum,divis^oor
phylum,subchvisioorsubphylum,classis,subclassis,ordo,subordo,familia,
sublamilia,tribus,subtribus,genus,subgenus,sectio,subsectio,series,subseries,
species,subspecies,varietas,subvarietas,lonna,sublorma.
Article4.2.Secondaryranksoltaxaarctribe(tribus)betweenlamilyand
genus,section(sectio)andseries(series)betweengenusandspecies,andvari-
ety(varietas)andlorm(forma)belowspecies.Termslortertiaryranksoftaxa
arcmadebyaddingtheprefix"sub-"tothetermsdenotingtheprincipaland/
orsecondaryranks.
Article4.3(sameasinroiuirrATitiN1).Furtherranksmayalsobeinterca-
latedoraddediiagreaternumberotrankso\taxa(beyondtertiaryranks)is
desired,providedthatconlusionorerrorisnottherebyintroduced.
Article5.1.Therelativeorderol theranksspecilicdinArt.3and4must
notbealtered(seeArt.33.7[ihcexamplesjoUowinii^.iyjwouldhebelterplaeed
here]and33.8).Anyolthesecondaryortertiaryranksmaybeomittedwithout
alteringtherelativeorder,butuseottertiaryranksmustfollowtheprincipalor
secondaryranksfromwhichtheyarederived.
Notea.—Agenusmaybeincludedinafamilywithoutreferencetoatribe
ortoasubfamily(omissionofoneorbothoftheranksbetweengenusandfam-
ilydoesnotalfecttherelativeorderol ranks);thenrankof subgenusmaybe
usedwithinagenuswithoutreferencetosections;therankofsubspeciesmay
beusedwithinaspecieswithoutrelcrcncetovarieties.
RanksofTaxainRelationtoBiology
Therankofsubspeciessometimesissaidtoapplytoataxonmore"species-
like"thanavarietyandforthisreasonshouldprecede"variety"inrelativeor-
derofrank.Inlraspecilicpopulationsystems,however,likespeciesthemselves,
varycontinuouslyindegreeofdifferentiationandreproductiveisolation,and
ifvarietiesandsubspeciesbotharetreatedasmorpho-geographictaxa,thena
biologicaldistinctionbetweenthetworanksisarbitrary.WeagreewithFred
Barrie(pers.comm.)thattheICBN"legislatesthenamesandrelativeorderof
ranks,notthetaxonomicconceptsattachedtoagivenranknorthefbiological]
conditionsunderwhichitisappropriatetouseoneoveranother."Thediscus-
sionhereoftheICBNstructureandintentaredetachedfromconsiderationsof
theimportanceorbiologicalsignificanceofranks.
ACKNOWLEDGMENTS
Prepai-ationolthisdiscussionwasprecipitatedbyKenCliambers,whobrought
toourattentionanotherCodeissue(includedinaneadyversionofthemanu-
NESOMANDLIPSCOMB,ICBNCLARIFICATION:USEOFRANKS 2191
script)—thatissueislesscomplexandapparentlywillberesolvedbytheICBN
EditorialCommitteebeforepublicationoftheViennaCode.Weappreciatethe
commentsofTomLammers,GerryMoore,RichRabeler,DickWunderlin,and
especiallythoseofFredBarrie(earlymanuscriptversion)andJohnStrother,
whichconsiderablysharpenedtheclarityofconceptsandpresentation.
REFERENCES
Greuter,W.etaI.(eds.).1988.Internationalcodeofbotanicalnomenclature,RegnumVeg.
118.KoeltzScientificBooks,Kdnigstein,Germany.
Greuter,W.etal.(eds.).1994.Internationalcodeofbotanicalnomenclature(TokyoCode).
RegnumVeg.131.KoeltzScientificBooks,Kdnigstein,Germany.
Greuter,W,etal.(eds.).2000.Internationalcodeofbotanicalnomenclature(SaintLouis
Code).RegnumVeg.138.KoeltzScientificBooks,Kdnigstein,Germany.
—
Greuter,W.andJ.McNeill.1993.Synopsisofproposalsonbotanicalnomenclature To-
kyo1993.AreviewoftheproposalsconcerningtheInternationalCodeofBotanical
NomenclaturesubmittedtotheXVInternational Botanical Congress.Taxon42:
191-271.
—
Greuter,W.,J.McNeill,andRR.Barrie.1993.Reportonbotanicalnomenclature Yokohama
1993.Englera14:1-265.
McNeill,J.1993.PreliminarymailvoteandreportofCongressactiononnomenclatural
proposals.Taxon42:907-922.
SiLVA,RC.1993.(290-320)Thirty-oneproposalsmainlyconcerningeditorialmatters,Taxon
42:185-190.