TurkJBot 30(2006)71-84 ©TÜB‹TAK ResearchArticle OntheTaxonomyofPlantaginaceae Juss. SensuLato: evidencefromSEMoftheSeedCoat AzzaA.SHEHATA* BotanyDepartment,FacultyofScience,AlexandriaUniversity,Alexandria,EGYPT MohammedHeshamA.LOUTFY BiologicalScienceandGeologyDepartment,FacultyofEducation,AinShamsUniversity,Roxy(Heliopolis)P.C.1134Cairo,EGYPT Received:15.02.2005 Accepted:25.10.2005 Abstract: SEMoftheseedcoatwasstudiedin41taxaofthePlantaginaceae sensulato.Thestudyincluded31taxaofPlantago L. and10taxathatwereformerlyassignedtothe Scrophulariaceae,representingthegeneraAntirrhinum L.,Digitalis L.,Linaria Mill. andVeronica L.TheobtaineddatawereanalysedbytheNTsys-PCprogrampackageusingtheUPGMAclusteringmethod.The studyshowedthat Veronica possessedcertainaffinitiesto Plantago species,thusgivingextrasupporttoearlierviewsthat Plantaginaceae sensustrictoandScrophulariaceae sensulatoarealliedthrough Veronica.Thestudyalsofavouredtheparaphylyof Plantago subgenusAlbicanssensu Rahn(1996)andtheretentionof P.camtschatica Link.subgenusPlantago L.andP.alpina L., P.crassifolia Forssk.andP.salsa Pall.subgenusCoronopus (Lam.&DC.)Rahnasdistincttaxa.Themonophylyof Plantaginaceae sensulato wasreassessedtoacertainextent. KeyWords: Plantaginaceae,Plantago,Scrophulariaceae,SEM,Seedcoat,Taxonomy Introduction classificationpresentedbyJuddetal.(1999)andAPG Plantaginaceae,asgenerallycircumscribed,isa (2003),theconceptofthePlantaginaceae wasbroadened cosmopolitanfamilyof3relatedgenera,i.e. Bougueria toincludemanygenerathatwereformerlyassignedto Decne., Littorella P.Bergiusand Plantago L.andabout the Scrophulariceae: Antirrhinum L.,Calceolaria L., 275speciesaredistributedindiversehabitatsthroughout Digitalis L.,Gratiola L.,Limnophila R.Br.,Linaria Mill., theworld(Cronquist,1981;Heywood,1993; Lindernia All.,Nemesia Vent., Penstemon Schmid., Mabberley,1997)oritisconsideredamonogeneric Scoparia L., and Veronica L.Theirviewwasbasedmainly familywithonlyPlantagoasrecognisedbyRahn(1996). onstudiesbasedonmolecularcriteria(Olmsteadetal., However,therelationshipsofthefamily,eitherwith 1992a,1992b,1993;Olmstead&Reeves,1995; otherfamiliesorbetweenitsgenera,arestillunclearand Wagstaff&Olmstead,1996).Thesestudiesshowedthat needtobeclarified(Heywood,1993;Albachetal., cpDNAcharacterssupportedthemonophylyofthe 2004).Regardingtherelationsbetweenitsgenera, Plantaginaceae sensulato(includingtheaddedgeneraof Bougueria and Littorella wereincludedin Plantago by the Scrophulariaceae).Moreover,Albachetal . (2004) Rahn(1996).Bentham&Hooker(1876)consideredthe addedmoregenerafromthe Scrophulariaceae tothe familyasrepresentingananomalousgroup.Sachs tribe Veroniceae nestedwithintheexpanded (1882)andGaebel(1933)placedthefamilynear Plantaginaceae.Althoughfewstudieshavebeencarried Verbenaceae.Severalauthorsstressedaclose outonPlantaginaceae sensulato,numerousstudieshave relationshipbetweenthe Plantaginaceae with beenperformedon Plantaginaceae sensustricto to Scrophulariaceae (Hallier,1912;Warming,1913; deducethephylogeneticrelationshipsamongitstaxa,yet Wettstein,1935;Corner,1976;Takhtajan,1980; themajorityofstudiesconcentratedon Plantago and Heywood,1993;Mabberley,1997).Moreover,ina utiliseddifferentcriteria,suchasmolecularsystematics *E-mail:[email protected] 71 OntheTaxonomyofPlantaginaceae Juss.SensuLato: evidencefromSEMoftheSeedCoat (Ronstedetal.,2002),chromosomenumbersand Scrophulariaceae: Antirrhinum, Digitalis, Linaria and karyology(Matsu&Noguchi,1989;Hamoudetal., Veronica (Appendix). 1993;PramanikandSen-Raychoudhuri,1997;Badr, Someofthesetaxawerecollectedfromseveral 1999;andseveralothers),anatomyandmorphology localitiesinEgypt,whiletherestwereobtainedfrom (AndrzejeuskaGolec,1992a,1992b;Park&Kim,1998; variousbotanicgardensinGermany,France,Italy,Spain Hosny&Waly,2001;andseveralothers)andpalynology andPortugal. (Saad,1986).However,theresultsofthesestudieswere Theexternalmacromorphologicalaspectsoftheseeds verydifferent,mainlybecausethetaxaincludedina ofthestudiedtaxawereinvestigatedwiththeaidofa certainstudywerenotthesameasthosepresentedin stereomicroscope.ForSEMobservations,driedmature anotherandtheyutiliseddifferentcriteria,andthuscould seedsweremountedonbrassstubsandcoatedwitha notbecomparedobjectivelyasHeywood(2001)pointed thinlayerofgoldusingJEOL-JFCL1100Eionsputtering. outinareviewarticleaboutthefutureofstudiesrelated Coatedseedswereexaminedandphotographedona tofloristicsandmonography. JEOL-JSM5300SEMwithanacceleratingvoltageof15 Asfarastheinfragenericclassificationof Plantago is kVattheElectronMicroscopicUnit,FacultyofScience, concerned,Pilger(1937)subdividedthegenusinto2 AlexandriaUniversity. subgenera, Plantago and Psyllium L.Rahn(1978) TheterminologyofStearn(1966)andBarthlott publishedarevisionofthegenusinwhichhedividedit (1981)wasadoptedtodescribetheSEMaspectsofthe into3subgenera,i.e. Plantago, Cornopus and Psyllium seedcoat. (Juss.)Harms&Reiche.Rahn(1996)proposedanew infragenericclassificationof Plantago.Inthis Forcreatingadatamatrixfornumericalanalysisof classification,thegenusincludes6subgenera: Plantago, theresults,therecordedcharacterswereanalysedbythe Cornopus,Albicans, Psyllium,Littorellaandthesubgenus NTsys-PCprogrampackage,usingUPGMAclustering Bougueria.Concerning Plantaginaceaesensustricto , (Rohlf,1989).Therelationshipsbetweenthestudied severalstudieshaveshownthatseedmicromorphology taxa,expressedbyaveragetaxonomicdistance canbeavaluabletoolinaddressingthephylogenyandthe (dissimilarity),weredemonstratedinaphenogram. relationshipsinthefamily(Misra1964a,1964b,Corner, 1976;Rezk,1980,1987;Kamel,2003;andseveral ResultsandDiscussion others).Barthlott(1981)statedthatSEMoftheseed coatcanbeagoodtaxonomicandphylogeneticmarkerat Themacromorphologicalaspectsofthestudiedtaxa thesubgenerictosubfamiliallevel. showedthattheseedshapeisvariable(oblong, cymbiform,ovate,fusiform,lenticular,rounded,angular, Theaimofthisstudywastotesttherelationships ellipsoidandreniform).Sizerangedfromrelativelylarge amongPlantagospeciesaswellasbetweencertaintaxa seeds(morethan5mmlong)in Plantagoamplexicaulis of Plantaginaceaesensulato (aspresentedinthe Cav.and P.tenuiflora Waldst.&Kit.tomediumsized classificationsystemofJuddetal.(1999)thatwere seeds(morethan3mmlong)inP.afraL.,P.albicansL., formerlyassignedtothe Srophulariaceae,utilisingdata P.arabicaBoiss.,P.arborescensPoir.,P.saxatilis M.and setsfromSEMoftheseedcoat.Theresultsarediscussed P.sempervirens Crantz.Therestofthestudiedtaxa inthelightofthecurrentsystemofclassificationof possessedseedslessthan3mmlong. Plantaginaceae (sensu Juddetal . 1999)andthe infragenericclassificationsofthegenus Plantago (Pilger, TheSEMoftheseedcoat’smicromorphologicalaspects 1937;Rahn,1978,1996). ispresentedin(Table1&FigureA[1-41]).The constructedphenogram(FigureB),basedonthecodingof 41applicablecharacterstatesbelongingto8characters MaterialsandMethods fromtheSEMoftheseedcoat,showsthefollowing: Theinvestigatedtaxaincluded31speciesof Plantago i) Mostoftheinvestigatedtaxathatwereformerly representingthesubgenera Albicans,Coronopus, assignedtotheScrophulariaceae (1,2,3,4,5,6,38,39, Plantago and Psyllium (sensu Rahn1996)and10taxa 40,41)werescatteredacrosstheconstructed belongingto4generathatwereformerlyassignedtothe phenogramalongwiththePlantagotaxa(FigureB). 72 Table1.Seedcoat'smicromorphologicalaspects. Character Anticlinalwalls Periclinalwalls Overall seedcoat Thickness Pattern Taxa pattern Cellshape Shape degree ofthickening Level Level Texture 1 Antirrhinummajus Reticulate Angular Slightly Thick Buttressedto Highlyraised ±flat Granulate undulate beaded 2 Digitalislanata Reticulate Angular Straight Slightlythick Smooth Highlyraised ±flat Ribbed 3 Digitalislutea Reticulate Angular Straight Thick Slightlybeaded Highlyraised Concave Ribbed tosmooth 4 Digitalisparviflora Reticulate Angular Straight Thick Slightlybeaded Highlyraised Concave Ribbed tosmooth 5 Linariapurpurea Verrucate Variable Straight Slightlythick Slightlybeaded Channeled Convex Granulate tosmooth 6 Linariatenuis Colliculate Variable Straight Slightlythick Slightlybeaded Channeled Convex Granulate tosmooth 7 Plantagoafra Scalariform Angular Straight Thin Irregular Channeled ±flat Microreticulate toreticulate 8 Plantagoalbicans Reticulate Angularto Slightly Slightlythick Buttressedto Raised ±flat Ruminate rounded undulate beaded 9 Plantagoalpina Reticulate Angular Slightly Slightlythick Irregular Raised ±flat Ruminate undulate 10 Plantagoaltissima Scalariform Angular Slightly Slightlythick Buttressedto Channeled ±flat Rugose toreticulate undulate beaded 11 Plantagoamplexicaulis Scalariform Angular Straight Slightlythick Irregular Raised ±flat Rugose toreticulate 12 Plantagoarborescens ScalariformAngular Straight Thin Buttressed Channeled Convex Ruminate tobeaded 13 Plantagoarenaria Scalariform Angular Straight Thin Buttressed Raised±flatScalariform tobeaded 14 Plantagoaschersonii Reticulate Angular Undulate Slightlythick Irregular Raised ±flat Ruminate A.A.SHEHATA,M.H.A.LOUTFY 15 Plantagoaustralis Reticulate Angular Straight Slightlythick Buttressed Raised Convex Striated tobeaded 16 Plantagobellardii. Reticulate Rounded Slightly Slightlythick Irregular Raised ±flat Reticulate undulate 17 Plantagocamtschatica ScalariformAngular Straight Thin Irregular Channelled Concave Ribbed 18 Plantagociliata Scalariform Angular Straight Thin Irregular Channelled ±flat Reticulate toreticulate 19 Plantagocoronopus Reticulate Undulate Undulate Slightlythick Irregular Raised ±flat Ruminate 73 20 Plantagocrassifolia Reticulate Undulate Undulate IrregularThick Raised ±flatRuminate 74 Table1.(Contunued). OntheTaxonomyof