Large-scale phylogenetic analysis of Amorphophallus (Araceae) derived from nuclear and plastid sequences reveals new subgeneric delineation

Remarkably little is known about the evolution of the emblematic genus Amorphophallus. To shed new light on phylogeneticrelationships between species of Amorphophallus and test its current classification, the first well-sampledmolecular phylogenetic analysis is presented here, comprising 157 species for which we generate nuclear (ITS1) andplastid (rbcL and matK) sequences. Our combined plastid and nuclear maximum likelihood and Bayesian inferencesprovide a solid backbone for subgeneric delineation in supporting the existence of four major clades. These latter cladesare here formally recognized as subgenera (two of which are new): Amorphophallus, Metandrium, Scutandrium andAfrophallus. Each subgenus is discussed based on selected morphological features and additional traits (e.g. distribution).Finally, our results strongly support the inclusion of the genus Pseudodracontium in Amorphophallus and therequired taxonomic changes are proposed here. In addition to clarifying species relationships in Amorphophallus andproposing a new infrageneric classification, this study provides a baseline for researchers working on the evolutionand biogeography of Araceae and more broadly on the tropical flora, especially in Southeast Asia