Division Bacillariophyta Engl. & Gilg (1919) see Phylum Bacillariophyta Engl. & Gilg (1919)
   Class Bacillariophyceae Haeckel (1878) - pennates
     Subclass Bacillariophycidae D.G.Mann (1990) - raphid diatoms
       Order Achnanthales P.C.Silva (1962)
         Family Achnanthaceae Kütz. (1844)
           1 Genus Achnanthesᵀ Bory (1822)