Alismatales: Order Alismatales

The APG II system, of 2003 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

  family Ruppiaceae

  family Scheuchzeriaceae

  family Tofieldiaceae

  family Zosteraceae

The order Alismatales contains 165 genera in 14 families.  Most plants are herbaceous and aquatic. The flowers are arranged in inflorescences and the mature seeds lack an endosperm.