Alismatales is an order of flowering plants. The order will of necessity contain the family Alismataceae. Taxonomy The APG II system, of 2003 (unchanged from the APG system, of 1998) assigns the order to the clade monocots and uses this circumscription: order Alismatales: family Alismataceae: family Aponogetonaceae: family Araceae: family Butomaceae : family Cymodoceaceae: family Hydrocharitaceae: family Juncaginaceae: family Limnocharitaceae: family Posidoniaceae: family Potamogetonaceae: fami… (More on Alismatales)