Floral anatomy of Magnolia decidua (Q.Y.Zheng) V.S.Kumar (Magnoliaceae): recognition of a partial pentamery

[摘要] FloralanatomyoftheendemicChinesespeciesMagnoliadecidua(Q.Y.Zheng)V.S.KumarwasstudiedinordertoclarifyitsdisputedrelationswithinthefamilyMagnoliaceae.Itsmoststrikingfeatureisachangeinfloralmerosity,clearlydemonstratedbythevasculature,thethreeperianthwhorlsbeingoftenpentamerous,whileonlythegynoeciummightbeconsideredastrimerous.Interestinglytheandroeciumexhibitsanintermediatecondition,asthestamensaresuppliedby15vasculartrunks,apatternreminiscentofthatpreviouslydescribedinMeiocarpidiumEngl.amp;Diels(Annonaceae),withtwolevelsof15trunkseach.Perianthpentamery,almostcompletelylackingsclerenchymaatanthesis,aswellasasharpseparationinthevascularsupplyoftheperianthandsexualparts,characterizeunmistakablythisspeciesfromallotherknownMagnoliaceae,eventhoughitsrelationshipwithMagnoliasect.Manglietiaisotherwisestrengthenedbystamenandcarpelpattern.Thisveryunexpectedpentamery—somewhatcomparabletothatofthemonocotgenusPentastemonaSteen.—isbrieflydiscussed.Thevalueofvascularanatomyasanadditionalbutessentialsourceofdatatocomplementthestandardphyllotacticandontogeneticapproachesusedfortheflower,isemphasizedagain.

[学科分类] 植物学

[关键词] Magnoliaceae;Magnolia;Manglietia;Sinomanglietia;cortical vascular system (CVS);floral anatomy;merosity;pentamery;Magnoliaceae;Magnolia;Manglietia;Sinomanglietia;systèmes vasculaires corticaux;anatomie florale;mérie;pentamérie