Oscillatoria nigro-viridis Thwaites ex Gomont
Macroscopically forming dark blue-green facsicles arranged more or less in parallel on the surface of substrate. Filaments long, occasionally with visible transparent sheath,
10-12 um wide. Trichomes clearly constricted near the granulated cross-walls, narrowing towards the apical parts. Cells with granulated cytoplasm, 2-4 um long. Apicals cells rouded,
sometimes slighty conical. Necridia present.
Taxonomic note: Well fit to the description, except the habitat (Oscillatoria nigro-viridis came from marine enviroment, in contrast to out morphotype).