In Ceará predominates a hot semiarid tropical climate. Different kinds of water courses can be found in the state, and representatives of Nymphaeaceae are frequently found on these. Of six genera belonging to this family, only Nymphaea occurs in Ceará. A total of seven Nymphaea species were identified. Nymphaea amazonum and N. lasiophylla have a wide distribution and occur from the coast to the interior of the state; N. jamesoniana, N. lingulata and N. pulchella are found in the semiarid regions of the interior of the state; N. rudgeana and N. tenerinervia have populations in coastal environments only. Nymphaea lasiophylla is the most frequent species. We present descriptions, comments, illustrations and identification keys for the taxa.
wetlands; floristics; aquatic macrophytes; semiarid regions