Molecular Phylogenetics and Morphological Analyses Support Dolichopoda, a New Neotropical Genus of Marantaceae (Zingiberales)

This study presents a molecular phylogenetic analysis based on four DNA regions (plastid <i>matK</i>, <i>trnL-trnF</i>, and <i>rps16</i> and nuclear ribosomal ITS) for <i>Ctenanthe</i>, <i>Saranthe</i> and <i>Stromanthe</i>, encompassing nearly 70% of species in these genera. Given this extensive sampling, we assess the monophyly of these genera and evaluate whether key morphological traits can serve as diagnostic characters (synapomorphies). For the first time, we included <i>Stromanthe bahiensis</i>, an unusual species that differs from all congeneric species in its elongate petioles and relatively long, pendulous, hirsute synflorescences. Our findings reveal <i>S. bahiensis</i> as sister to the rest of the group. The evolution of key morphological traits (organization of the aerial shoot system, rachis flexuosity, spathe compactness and cymule type) were estimated to be complex, with none exhibiting consistent diagnostic utility. Given that these traits were among the main reasons <i>S. bahiensis</i> was described under <i>Stromanthe</i>, our ancestral state reconstruction, coupled with its phylogenetic position, justifies recognition of a new genus, <i>Dolichopoda</i>. Our findings suggest that morphological evolution in the group may have been shaped by convergence, parallelisms and reversals, which may partially explain the high morphological overlap observed among genera. This realignment not only resolves phylogenetic inconsistencies but also facilitates more accurate biogeographic and ecological inferences. Additionally, we transfer <i>Ctenanthe dasycarpa</i> to <i>Stromanthe</i> to make <i>Ctenanthe</i> and <i>Stromanthe</i> mutually monophyletic.