a family of dicotyledonous plants similar in appearance to plants of the family Nymphaeaceae, with which it is sometimes combined. The Nelumbonaceae differ from the Nymphaeaceae in the structure of the gynoecium, the seeds, and the chromosomes. The plants are characterized by the combination of dicotyledonous and monocotyledonous features. One monocotyledonous feature is the diffuse arrangement of the conducting bundles in the rhizome. The family has one genus, Nelumbo.