Kingdom Plantae Haeckel (1866) - plants
   Subkingdom Rhodoplantae G.W.Saunders & Hommers. (2004)
     Phylum Rhodophyta Wettst. (1901) - red algae
       Subphylum Eurhodophytina G.W.Saunders & Hommers. (2004)
         Class Florideophyceae Cronquist (1960)
           Subclass Rhodymeniophycidae G.W.Saunders & Hommers. (2004)
             Order Gracilariales Fredericq & Hommers.
               1 Family Gracilariaceae Nägeli (1847)
               2 Family Pterocladiophyllaceae Kraft (1981), orth. inval. see Family Pterocladiophilaceae Fan & Papenfuss (1959)