Abstract: This review summarizes the recent ideas on (1) the systematics of Nelumbonaceae; ( 2) the classification of lotus cultivars; and (3) genetic diversity of lotus. The plants of the Nelumbonaceae were formerly grouped in the Nymphaeaceae. Evidences from comparative morphology, cytology, palynology and embryogenesis etc. supported Nelumbonaceae as a family in Nymphaeales, Ranunculales or Nelumbonales. Recent phylogenetic reconstruction based on DNA sequence demonstrated that Nelumbonaceae is a basal family of eudicots, closely related to Proteaceae and Planataceae. It is generally accepted and reconfirmed that Nelumbonaceae is consisted of two disjunct species, N. nucifera and N. lutea, though their hybrids are fertile. China has a very long history of cultivation of N. nucifera, over 600 cultivars are now under cultivation. Hybridization between cultivars complicated the relationships among cultivars. The genetic variations of lotus have not been well understood, especially for wild lotus. Genetic diversity revealed bymolecular markers overestimated the actual levels due to lumping together the cultivars of the two species.

Key words: Nelumbonaceae