Phylogenetics of Brazilian phyllocladiferous Phyllanthus (Phyllanthaceae): a new section exclusive from the Atlantic Rain Forest, with morphological and molecular support

The latest phylogenetic and taxonomic studies emphasizing Phyllanthus (Phyllanthaceae) have significantly altered the relationships between its taxa. In this work, we inferred a phylogeny for the Brazilian phyllocladiferous species of Phyllanthus, traditionally included within Phyllanthus sects. Choretropsis and Xylophylla from eastern Brazil and Caribbean, respectively. Our analysis demonstrated that Brazilian phyllocladiferous species has no relation to P. sect. Xylophylla from the Caribbean, but sect. Choretropsis, as it currently stands, does not form a monophyletic group. Thus, phylloclades arose in Phyllanthus at least in five distinct clades. Most species of sect. Choretropsis are recovered among representatives of other groups (sects. Antipodanthus and Phyllanthus subsect. Claussenianii), but no macromorphological feature could be traced for the clades we recovered. One exception is a clade containing P. dracenoides, P. gladiatus and P. pedicellatus, species with dracenoid habit and exclusive to the humid dense forests along Atlantic Forest domain, for which we describe a new section.