Two form-genera of aerophytic heterocytous cyanobacteria from Brasilian rainy forest "Mata Atlântica".

Two specific and characteristic morphotypes of the cyanobacterial heterocytous and heteropolar genera from the family Microchaetaceae were recognized in subaerophytic, epiphytic, epidendric and soil habitats in Brasilian rainy forest "Mata Atlântica". The modern taxonomy of cyanobacteria is based mainly on molecular sequencing; the both new types were not yet cultured and their genetic relations must be solved in future. However, they can not be included in any generic unit supported by genetic methods and correspond morphologically to quite special and phenotypically yet unknown generic entities. Therefore, new form-genera Ophiothrix and Streptostemon are described. Few subtypes, which can be designated as new species according to traditional cyanobacterial taxonomy, were recognised from both these genera. Another tropical cyanobacterium "Scytonema hansgirgii Schmidle", described from the similar habitat (bark of trees) in Indonesia and central Africa, belongs evidently also to the genus Ophiothrix.