Phylum Magnoliophyta Cronquist, Takht. & Zimmerm. ex Reveal (1996) see Infraphylum Angiospermae auct.
   Class Magnoliopsida Brongn. (1843)
     Subclass Rosidae Takht. (1967) see Superorder Rosanae Takht. (1967)
       Superorder Rosanae Takht. (1967)
         Order Rosales Bercht. & J.Presl (1820)
           Family Rosaceae Juss. (1789), nom. cons. - rose family
             Subfamily Spiraeoideae Arn. see Tribe Spiraeeae
               Tribe Spiraeeae
                 Genus Petrophytum (Nutt. ex Torr. & A.Gray) Rydb.