Phylum Magnoliophyta Cronquist, Takht. & Zimmerm. ex Reveal (1996) see Infraphylum Angiospermae auct.
   Class Magnoliopsida Brongn. (1843)
     Subclass Caryophyllidae Takht. (1967) see Order Caryophyllales Juss. ex Bercht. & J.Presl (1820)
       Superorder Polygonanae Takht. ex Reveal (1992) see Order Caryophyllales Juss. ex Bercht. & J.Presl (1820)
         Order Polygonales Dumort. (1829) see Order Caryophyllales Juss. ex Bercht. & J.Presl (1820)
           Family Polygonaceae Juss. (1789), nom. cons. - buckwheat family
             Subfamily Polygonoideae Eaton
               Tribe Polygoneae
                 1 Genus Polygonum L. (1753) - knot grass
                 2 Genus Fagopyrum Mill. (1754)
                 3 Genus Persicaria (L.) Mill. (1754)
                 4 Genus Knorringia (Czukav.) Tzvelev. see Genus Persicaria (L.) Mill. (1754)
                 5 Genus Koenigia L. (1767)
                 6 Genus Oxygonum Burchell ex Campderá (1819)