Phylogeny and circumscription of <i>Dasyphyllum</i> (Asteraceae: Barnadesioideae) based on molecular data with the recognition of a new genus, <i>Archidasyphyllum</i>

<i>Dasyphyllum</i> Kunth is the most diverse genus of the South American subfamily Barnadesioideae (Asteraceae), comprising 33 species that occur in tropical Andes, Atlantic Forest, Caatinga, Cerrado, and Chaco. Based on distribution, variation in anther apical appendages, and leaf venation pattern, it has traditionally been divided into two subgenera, namely, <i>Archidasyphyllum</i> and <i>Dasyphyllum</i>. Further, based on involucre size and capitula arrangement, two sections have been recognized within subgenus <i>Dasyphyllum</i>: <i>Macrocephala</i> and <i>Microcephala</i> (=<i>Dasyphyllum</i>). Here, we report a phylogenetic analysis performed to test the monophyly of <i>Dasyphyllum</i> and its infrageneric classification based on molecular data from three non-coding regions (<i>trn</i>L-<i>trn</i>F, <i>psb</i>A-<i>trn</i>H, and ITS), using a broad taxonomic sampling of <i>Dasyphyllum</i> and representatives of all nine genera of Barnadesioideae. Moreover, we used a phylogenetic framework to investigate the evolution of the morphological characters traditionally used to recognize its infrageneric groups. Our results show that neither <i>Dasyphyllum</i> nor its infrageneric classification are currently monophyletic. Based on phylogenetic, morphological, and biogeographical evidence, we propose a new circumscription for <i>Dasyphyllum</i>, elevating subgenus <i>Archidasyphyllum</i> to generic rank and doing away with the infrageneric classification. Ancestral states reconstruction shows that the ancestor of <i>Dasyphyllum</i> probably had acrodromous leaf venation, bifid anther apical appendages, involucres up to 18 mm in length, and capitula arranged in synflorescence.