Kingdom Plantae Haeckel (1866) - plants
   Subkingdom Rhodoplantae G.W.Saunders & Hommers. (2004)
     Phylum Rhodophyta Wettst. (1901) - red algae
       Subphylum Metarhodophytina G.W.Saunders & Hommers. (2004) [monotypic]
         1 Class Compsopogonophyceae G.W.Saunders & Hommers. (2004)