Molecular Phylogenetics and Trait Evolution in Stigmatodon (Bromeliaceae, Tillandsioideae), an Endemic Genus to Brazilian Rocky Outcrops

<strong><em>Abstract</em></strong>—The genus <em>Stigmatodon</em> occurs in steep granite slopes, typical of the inselbergs from the Brazilian Atlantic Forest. Here, we present the first broad phylogenetic analysis focused on <em>Stigmatodon</em>, sampling a total of 83 terminals, including 16 of the 20 species of the genus and the morphologically similar species of <em>Vriesea</em>. We conducted a phylogenetic analysis using two plastid markers (<em>matK </em>and <em>rps16-trnK</em>) and the nuclear gene <em>PHYC</em> to infer phylogenetic relationships and reconstruct ancestral states for ecological and morphological characters. Our results suggest the monophyly of <em>Stigmatodon</em> as originally circumscribed is only possible with the inclusion of morphologically and ecologically similar <em>Vriesea</em> species. In addition, the morphological and anatomical traits led us to propose a new circumscription for the genus, combining eight species of <em>Vriesea </em>to <em>Stigmatodon</em>. The stomata positioned above the ordinary epidermal cells, the adaxial water-storage parenchyma with axially elongated cells, the stamens positioned in two groups of three on each side of the corolla and the tubo-laciniate stigma are exclusive to <em>Stigmatodon</em> in its new circumscription. This new morphological and phylogenetic results constitute a relevant contribution to the taxonomy and evolution of Bromeliaceae, one of the most diverse and ecologically important families of flowering plants of the Neotropics.