The Viruá National Park (VNP) with its different plant formations (rainforest, white-sand savannas —“campinaranas,” and “buritizais”) is located in a region still lacking in botanical studies (Guiana Shield and Brazilian Amazon). Aiming to improve the knowledge of the region's flora, collections were conducted in VNP from 2010 to 2015. The present work provides a taxonomic treatment of the aquatic and palustrine members of Nymphaeales, Alismatales, Dioscoreales, and Arecales. It includes identification keys to species, as well as descriptions, illustrations, and comments on taxonomy, ecology and geographical distribution. A dichotomous key to all families with at least one aquatic or palustrine species found in VNP is also provided.