Systematics of Ditaxinae and Related Lineages Within the Subfamily Acalyphoideae (Euphorbiaceae) Based on Molecular Phylogenetics

The subtribe Ditaxinae in the plant family Euphorbiaceae is composed of five genera (, , , and ) and approximately 120 species of perennial herbs (rarely annual) to treelets. The subtribe is distributed throughout the Americas, with the exception of , which also occurs in tropical Africa and Madagascar. Under the current classification, Ditaxinae includes genera with a questionable morphology-based taxonomy, especially , and . Moreover, phylogenetic relationships among genera are largely unexplored, with previous works sampling <10% of taxa, showing Ditaxinae as paraphyletic. In this study, we inferred the phylogenetic relationships within Ditaxinae and related taxa using a dataset of nuclear (ETS, ITS) and plastid (D, LF, TL) DNA sequences and a wide taxon sampling (60%). We confirmed the paraphyly of Ditaxinae and , both with high support. Following our phylogenetic results, we combined in and upgraded Ditaxinae to the tribe level (Ditaxeae). We also established and described the tribe Caperonieae based on , and transferred to the tribe Adelieae, along with , , and . Finally, we discuss the main morphological synapomorphies for the genera and tribes and provide a taxonomic treatment, including all species recognized under each genus.