Floristic survey of herbaceous and subshrubby aquatic and palustrine angiosperms of Viruá National Park, Roraima, Brazil.

We provide and discuss a floristic survey of herbaceous and subshrubby aquatic and palustrine angiosperms of Viruá National Park (VNP). The VNP is located in the northern Amazon basin and displays phytophysiognomies distributed in a mosaic where these plants occur, as flooded forests, hydromorphic white-sand savannas, "buritizais" and waterbodies. After expeditions between February/2010 and January/2015 and the analysis of specimens from regional herbaria, we list 207 species of herbaceous and subshrubby aquatic and palustrine angiosperms for the VNP, distributed in 85 genera in 37 families. We recorded six new occurrences for Brazil, two for the northern Brazilian region and 21 for Roraima state. These new occurrences, added to the other species listed here, highlight the floristic similarity between the study site and the Guiana Shield, an adjacent phytogeographical unit and geologically related to the origin of white-sand savannas.