[plants] Haeckel (1866) - plants
   vascular plants see Phylum Tracheophyta Sinnott ex Caval.-Sm. (1998)
     euphyllophytes see Clade Euphyllophyta Lecointre & Le Guyader 2006 [Cantino & Donoghue 2020]
       Spermatophyta Britton & Brown 1896 [Crane & Kenrick 1997], nom. cl. inval. - seed plants see Clade Spermatophyta Britton & Brown 1896 [Cantino, Doyle & Donoghue 2020]
         Class Magnoliopsida Brongn. (1843)
           Magnoliidae s.s. Novák ex Takht. (1967) - angiosperms
             Order Piperales Bercht. & J.Presl (1820)
               Family Aristolochiaceae Juss. (1789), nom. cons. - birthwort family
                 Subfamily Aristolochioideae Burnett
                   1 Genus Thottea Rottboell (1783)
                   2.1.1 Genus Aristolochia L. (1753) - birthworts
                   2.1.2 Genus Einomeia Raf.
                   2.1.3 Genus Euglypha R. Chodat & E. Hassler (1906)
                   2.1.4 Genus Howardia Klotzsch (1859), nom. illeg.
                   2.1.5 Genus Isotrema Rafinesque (1819)
                   2.2 Genus Holostylis Duchartre (1854)