Aquatic macrophytes of floating mats ("baceiros") in the Abobral and Miranda Pantanal Wetlands, Mato Grosso do Sul State, Brazil). The association between floating and epiphytic biological forms, regarding aquatic macrophytes, creates what are called floating mats. This concept refers to the establishment of one or more epiphytes on live individuals of floating species, as a synonym of "camalotal," or applied to floating vegetation that grows on organic soil in decomposition (histosol). A checklist of species was made of five floating mats in the Abobral and Miranda Pantanal Wetlands and floristic similarities among these mats were calculated to show aspects of sucessional dynamics on floating mats. A total of 66 species of epiphytic aquatic macrophytes were found, distributed in 27 families, Cyperaceae and Poaceae being the most representative. The number of species per mat varied from 7 and 39, with some taxa common to all mats, such as Ludwigia leptocarpa (Nutt.) H. Hara and Oxycaryum cubense (Poepp. & Kunth) Palla, at the specific level, and Asteraceae, Cyperaceae, Onagraceae, Poaceae and Polygonaceae, at the family level. Other biological forms besides epiphytes were found associated with "baceiros" or adapted to histosol conditions, being considered "casual epiphytes". "Baceiros" in similar successional stages of development have high floristic similarity, and in general, the more advanced the natural succession, the higher the number of species.