Angiosperms - flowering plants see Subclass Magnoliidae Novák ex Takht. (1967)
   Mesangiosperms see Clade Mesangiospermae Donoghue, Doyle & Cantino 2007 [Donoghue, Doyle & Cantino 2020]
     Monocots see Clade Monocotyledoneae de Candolle 1817 [Judd, Soltis, Soltis & Graham 2020]
       Order Alismatales R.Br. ex Bercht. & J.Presl (1820)
         28 Family Araceae Juss. (1789), nom. cons. - Arum family
         29 Family Tofieldiaceae Takht. (1995)
         30 Family Alismataceae Vent. (1799), nom. cons. - water-plantain family
         31 Family Butomaceae Mirb. (1804), nom. cons. - flowering rush family
         32 Family Hydrocharitaceae Juss. (1789), nom. cons. - tape-grass family
         33 Family Scheuchzeriaceae F.Rudolphi (1830), nom. cons.
         34 Family Aponogetonaceae Planch. (1856), nom. cons. - Cape-pondweed family
         35 Family Juncaginaceae Rich. (1808), nom. cons. - arrow-grass family
         36 Family Maundiaceae Nakai (1943)
         37 Family Zosteraceae Dumort. (1829), nom. cons.
         38 Family Potamogetonaceae Bercht. & J.Presl (1823), nom. cons. - pondweed family
         39 Family Posidoniaceae Vines (1895), nom. cons.
         40 Family Ruppiaceae Horan. (1834), nom. cons. - ditch-grass family
         41 Family Cymodoceaceae Vines (1895), nom. cons. - Cymodocea family