An update on the knowledge of aquatic macrophytes in Northeast Brazil

Abstract We updated the first checklist of aquatic macrophytes from Northeast Brazil (First Flora), which included data collected up to 2010, with a new checklist based on data from works published between 2011 and 2017 (New Flora). Together, these checklists record 637 species of 89 families, with an emphasis on strictly amphibious or emergent species, with 392 and 115 species, respectively. We found differences in observed richness between New Flora and First Flora, with an increase of 106 species in the New Flora. The rarefaction curve shows that a considerable increase in collection effort is necessary to determine the aquatic flora of the studied region. From the compiled data, we suggest new perspectives for floristic inventories of aquatic macrophytes, highlighting the prioritization of poorly studied areas; the exploration of ecological information of the species (e.g., endemism, rarity, threat of extinction or invasive potential); and the promotion of projects on a regional scale.