[organisms] see Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
   Eukaryota Chatton, 1925 - eukaryotes see Domain Eukaryota Chatton, 1925
     Class Bacillariophyceae Haeckel (1878) - pennates
       Subclass Bacillariophycidae D.G.Mann (1990) - raphid diatoms
         Order Achnanthales P.C.Silva (1962)
           Family Achnanthaceae Kütz. (1844)
             Genus Achnanthes Bory (1822)
               Achnanthes brevipes C.Agardh (1824)