The Atlantic Forest is a hotspot for biodiversity conservation because of its high levels of endemism and threatened areas. Three main forest types, differentiated by their floras, compose the Atlantic Forest: ‘Atlantic Forest’ sensu strictu , ‘Araucaria Mixed Forest’ and ‘Seasonal Forest’. The flora comprises taxa from the Amazon forest, Cerrado gallery forests and the Andean region, which makes the Atlantic Forest a relevant study system for ecologists and biogeographers. Here, we present data from 206 floris- tic checklists describing the occurrence of 1,916 species across the southern portion of the Atlantic Forest. This dataset can be useful for understanding mechanisms underlying plant community assembly processes and the historical relationships between different forest formations.