The Chapada das Mesas National Park is a federal reserve located in the State of Maranhão, in an ecotonal region of the Brazilian Northeast Cerrado. Aiming to assess the influence of biogeographic patterns and support restoration actions for regions where information is scarce, we analyzed the floristic composition of savanna and forest Cerrado physiognomies, the floristic relationships with other Brazilian Cerrado areas and investigated the floristic relationships between the Cerrado and the Amazon, and the Caatinga and Atlantic Forest biomes. A total of 242 species in 181 genera and 64 families are recorded in our study. Fabaceae was the most representative family. We report 50 new records of species for Maranhão, four new records for the Cerrado biome and one vulnerable species. The separation of the gallery forest from cerradão and typical cerrado by ordination shows the influence of water availability and soil characteristics on floristic composition. In Cerrado ecotonal regions, such as Mato Grosso and Maranhão, the presence of species shared with the Amazon is expressive. In addition to the Amazon, physiognomies had greater floristic connection with the Caatinga flora. Our data demonstrates that the marginal areas of the Brazilian Cerrado may present high species diversity.

— A new species of Dyckia (Bromeliaceae, Pitcairnioideae) from Maranhão, Northeastern Brazil is described and illustrated. Dyckia maranhensis is endemic in the cerrado phytogeographic domain and it was erroneously identified as D. braunii Rauh in herbarium collections. Information on its phenology, distribution, and conservation status is provided. The species is morphologically compared to D. dissitiflora Schult. & Schult. f., which is the most similar species.