CONICET | Buscador de Institutos y Recursos Humanos

AbstractThe ﬂoral biology of Aristolochia argentina (Aristolochiaceae) was studied in natural populations in Co´ rdoba,Argentina. This native vine has ﬂowers that attract mainly scuttle ﬂy pollinators of the genus Megaselia (Phoridae).The trap-like perianth is formed by a limb, a tube, and a basal utricle. The limb produces an odor that recalls decayingplant tissues, which apparently mimics the natural oviposition substrate of the ﬂies. The insects stay entrapped insidethe utricle for approximately 24 h, making contact with the sexual organs of the ﬂower. When released, they canbecome captured again in other ﬂowers. The mechanisms of herkogamy and protogyny are efﬁcient. Although selfcompatibilityexists, as demonstrated by the high percentage of fruits produced by geitonogamy, fruits were notproduced under natural or artiﬁcial autogamous conditions. Natural pollination showed signiﬁcantly lower fruit setthan xenogamous and geitonogamous crosses.