What actually is <i>Vriesea</i>? A total evidence approach in a polyphyletic genus of Tillandsioideae (Bromeliaceae, Poales)

The taxonomic delimitation of Vriesea is challenging because several diagnostic traits of the genus are shared with other genera in Tillandsioideae. The genus has no unique morphological features that distinguish it from other taxa. Earlier phylogenetic studies suggested a polyphyletic status of this genus, but taxon sampling was limited, and tests of congruence for morphological characters have not yet been performed. Here we used a total evidence approach and a more comprehensive Brazilian taxon sampling to help circumscribe Vriesea s.s. (the lineage that contains the type species). We concatenated morphological and molecular datasets for the first time to reconstruct phylogenetic hypotheses. We used 99 morphological characters and ~4 kb of plastid data (psbA-trnH, trnK5'-rps16, matK, trnL-trnF) for 172 terminals, including nine genera of Tillandsioideae. We analysed datasets by parsimony analyses, with several weighting schemes considered for character-state changes (equal weights and an implied weighting scheme that we used as a sensitivity analysis). The concatenated data resulted in a well-resolved phylogenetic inference that provided strong evidence that the genus is not monophyletic as traditionally circumscribed. Given the congruence between morphological, molecular and geographical sources of data, we separated Vriesea into distinct lineages, and proposed a new circumscription that includes only species of Vriesea s.s. found in the Chacoan and Parana subregions.