The subtribe Ditaxinae in the plant family Euphorbiaceae is composed of five genera (
Argythamnia,
Caperonia,
Chiropetalum,
Ditaxis and
Philyra) and approximately 120 species of perennial herbs (rarely annual) to treelets. The subtribe is distributed throughout the Americas, with
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The subtribe Ditaxinae in the plant family Euphorbiaceae is composed of five genera (
Argythamnia,
Caperonia,
Chiropetalum,
Ditaxis and
Philyra) and approximately 120 species of perennial herbs (rarely annual) to treelets. The subtribe is distributed throughout the Americas, with the exception of
Caperonia, which also occurs in tropical Africa and Madagascar. Under the current classification, Ditaxinae includes genera with a questionable morphology-based taxonomy, especially
Argythamnia,
Chiropetalum and
Ditaxis. 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 (
petD,
trnLF,
trnTL) DNA sequences and a wide taxon sampling (60%). We confirmed the paraphyly of Ditaxinae and
Ditaxis, both with high support. Following our phylogenetic results, we combined
Ditaxis in
Argythamnia and upgraded Ditaxinae to the tribe level (Ditaxeae). We also established and described the tribe Caperonieae based on
Caperonia, and transferred
Philyra to the tribe Adelieae, along with
Adelia,
Garciadelia,
Lasiocroton and
Leucocroton. Finally, we discuss the main morphological synapomorphies for the genera and tribes and provide a taxonomic treatment, including all species recognized under each genus.
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