Class Conjugatophyceae Engl. (1892) see Class Zygnematophyceae Round ex Guiry (2013)
   Order Zygnematales - filamentous conjugates and saccoderm desmids
     Family Mesotaeniaceae
       Genus Planotaenium (Ohtani) Petlovany & Palamar-Mordvintseva (2009)
         1 Planotaenium interruptum (Bréb. ex Ralfs) Petlovany & Palamar-Mordvintseva