Agradecimentos: AVS thanks the Programa de Pós - graduação em Biologia Vegetal and CNPq for the Ph.D. scholarship. VCS thanks CNPq for a productivity grant. AOS thanks FAPESP (2012/12927-9) for financial support. We thank ICMBio and IEF for collecting permits; the curators of cited herbaria for making all specimens available; Gustavo H. Shimizu, João A. M. do Carmo, Nara F. O. Mota, Gabrial Piassa, Caio G. Pereira, Paulo Baleeiro, Paulo M. Gonella, Igor Lins, and Fernando Rivadavia for field support; Luciano P. Queiroz for providing samples of Philcoxia maranhensis; G. H. Shimizu and Leonardo J. Leitão for kindly providing some of the photographs; and especially Raquel M. Machado for patiently preparing all figures presented in this contribution. We also thank Dr. Andreas Fleischmann and an anonymous reviewer for suggestions that helped improve our manuscript; and Dr. Austin Mast for authorizing the reproduction of Fig. 2 from Scatigna et al. (2017a) Ver menos

Philcoxia (Plantaginaceae, Gratioleae) is a genus with seven species of small herbs endemic to Brazil. It is characterized by underground stems and petioles, peltate leaves, and zigzag racemose inflorescences, in addition to a remarkable carnivorous syndrome. The phylogenetic placement of Philcoxia within tribe Gratioleae has been uncertain since its discovery due to its unique morphology and limited data from phylogenetic studies. We tested the phylogenetic placement of Philcoxia within Gratioleae, increasing the number of species sampled within both the genus and the rest of the tribe, and sequencing four regions from cpDNA (rpl16, rps16, and trnL introns and the trnL-trnF intergenic spacer) and one from nrDNA (ITS1 spacer); we used both parsimony and Bayesian inference to reconstruct the phylogeny. Moreover, we assessed both the monophyly of the genus and interspecific relationships. Finally, we performed ancestral character state reconstructions of 10 morphological characters to infer synapomorphies for the genus and specific clades within it. Philcoxia was recovered as monophyletic, with maximum support values, as sister to Stemodia stellata. Five morphological character states were reconstructed as potential synapomorphies for the Philcoxia clade (rosetted herb habit, underground stems and petioles, floral resupination, number of stamens reduced to two, and number of fertile thecae per anther reduced to one), whereas fourwere reconstructed as potential synapomorphies for specific clades within the genus (peltate leaves, irregular rosettes, vegetative propagation by rhizomes, and presence of tubers). Further anatomical studies, in association with ecological data, would provide insight into the structure of the underground systems and its adaptive significance, and would further elucidate the evolution of carnivory in Philcoxia. Our study highlights the need to reassess the concepts and circumscriptions of some currently accepted genera of the Gratioleae such as Bacopa, Conobea, and Stemodia, and for the tribe Angelonieae Ver menos