Studies of stream macroalgal communities in Brazil are almost exclusively based on data from São Paulo state. There are no extensive studies concerning stream macroalgae in Paraná state. In this context, the main objective of this study was to survey the flora of stream macroalgal communities in the Serra da Prata, a well-preserved and protected area of dense Atlantic rain forest. Sampling was carried out in 14 stream segments. The survey resulted in the identification of 19 taxa (15 infrageneric, three generic and one life cycle stage of Batrachospermum spp.), distributed in four divisions. Cyanophyta was the division with the highest number of taxa (58% of the species) and Microcoleus subtorulosus Gomont ex Gomont was the most widespread species. Most of the taxa identified (53%) were recorded for the first time in Paraná state, while others were considered rare in Brazilian streams. These results reinforce the importance and necessity of more floristic and taxonomic studies in order to increase our knowledge of stream macroalgal community biodiversity.
macroalgae; streams; Cyanophyta; floristic survey