gen. nov., sp. nov. and gen. nov., sp. nov., epiphyllic cyanobacteria associated with leaves.

Cyanobacteria dwelling on the salt-excreting leaves of the mangrove tree were isolated and characterized by ecological, morphological and genetic approaches. Leaves were collected in a mangrove with a history of oil contamination on the coastline of São Paulo state, Brazil, and isolation was achieved by smearing leaves on the surface of solid media or by submerging leaves in liquid media. Twenty-nine isolated strains were shown to belong to five cyanobacterial orders (thirteen to , seven to , seven to , one to , and one to ) according to morphological and 16S rRNA gene sequence evaluations. More detailed investigations pointed six Rivulariacean and four Xenococcacean strains as novel taxa. These strains were classified as gen. nov. (type species sp. nov. with type strain CENA341) and gen. nov. (type species sp. nov. with type strain CENA333), according to the International Code of Nomenclature for Algae, Fungi, and Plants. This investigation shows some of the unique cyanobacteria inhabiting the phyllosphere of can be retrieved by culturing techniques, improving current taxonomy and providing new insights into the evolution, ecology, and biogeography of this phylum.