Natura - nature
   actualia - actual entities
     Mundus Plinius - physical world
       naturalia - natural bodies
         [crown] Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
           Domain Bacteria Woese et al. 1990 [paraphyletic?]
             Superphylum Terrabacteria Battistuzzi et al. 2004
               Phylum Cyanobacteria (ex Stanier 1974) Cavalier-Smith 2002 - cyanobacteria
                 Class "Cyanobacteria" Cavalier-Smith, 2002
                   Subclass Nostocophycideae
                     Order Nostocalesᵀ Borzì (1914)
                       Family Hapalosiphonaceae Elenkin (1917), nom. cons.
                         Genus Fischerella (E. Bornet & C. Flahault) M. Gomont (1895)
                           Fischerella ambigua (C. Nägeli in F.T. Kützing ex E. Bornet and C. Flahault) M. Gomont 1895