Kingdom Chlorobiota C.Jeffrey ex Doweld (2001) - plants see Subkingdom Viridiplantae Caval.-Sm. (1981)
   Subkingdom Lycopodiobiotina Doweld (2001)
     Division †Langiophytophyta Doweld (2001) [monotypic] see Phylum Langiophytophyta Doweld (2001)
       Class †Langiophytopsida Doweld (2001)
         Order †Langiophytales Doweld (2001) [monotypic]
           Family †Langiophytaceae Doweld (2001)
             Genus †Caia Fanning, D.Edwards & J.B.Richardson (1990)