XVI International Botanical Congess

Molecular and morphological analyses indicate that Dioscoreales is in need of recircumscription. Contrary to previous classifications, Burmanniaceae and Nartheciaceae are now considered as belonging within the order, although Burmanniaceae has unusual floral structures, difficult to homologise with those of putatively related taxa. Within Dioscoreaceae sensu lato, relationships of the hermaphrodite taxa (Avetra, Trichopus and Stenomeris) have never been fully resolved. Addition of these taxa to phylogenetic analyses has helped to resolve the position of Dioscoreales within the monocots. Floral micromorphological characters have been important in testing phylogenetic hypotheses produced by molecular analyses, whilst the molecular phylogeny provides a framework on which to investigate evolution and development of floral characters.