alismaceous
/ˌalɪzˈmeɪʃəs/Botany. Now rare
adjective
Characteristic of or belonging to the former family Alismaceae (now Alismataceae), comprising monocotyledonous aquatic and marshland plants found chiefly in north temperate regions, of which Alisma is the type genus.
Origin
Mid 19th century. From alisma + -aceous, after scientific Latin Alismaceae, former family name.