A floristic survey was carried out in a contact area between Araucaria Forest and Seasonal Forest areas, in the municipality of Guaraciaba, Far West of Santa Catarina state, southern Brazil. We provide a checklist containing 108 species and 42 plant families for the area. Families with the most encountered number of species were Myrtaceae (eight species), Solanaceae (eight), Euphorbiaceae (seven) and Poaceae (six). Two species are classified as endangered of extinction, following IUCN criteria. An analysis using UPGMA algorithm and species composition comparisons using additional 6 areas of Araucaria Forest and 6 areas of Seasonal Forest showed its greater relationship to other Araucaria Forest areas, but also the influence of the adjacent Seasonal Forest areas in the floristic composition of the surveyed area.