- Alismatidae, subclass Alismatidae - one of four subclasses or superorders of Monocotyledones; comprises about 500 species in 14 families of aquatic and semi-aquatic herbs
--1 is a kind of class
--1 is a member ofMonocotyledones, class Monocotyledones, Monocotyledonae, class Monocotyledonae, Liliopsida, class Liliopsida