The species of Guatteria from the state of Rio de Janeiro are presented. The genus is the largest within the Annonaceae, with about 265 species, and is also the most complex one because of the difficulties in delimiting species and sections. These difficulties are due to the similarity of reproductive features between species and huge variation in vegetative features within species. As a result, 13 species of Guatteria are recognized in Rio de Janeiro: Guatteria burchellii, G. candolleana, G. elliptica, G. ferruginea, G. glabrescens, G. latifolia, G. mexiae, G. nigrescens, G. pohliana, G. pubens, G. reflexa, G. villosissima and G. xylopioides, and 16 names are synonymized. Key to the species, descriptions, comments about taxonomy, phenological information and notes on habitats are provided.
flora; Atlantic Forest; systematic; taxonomy; identification; geographical distribution