Cabaña Fader, A.A., E. Bezerra de Souza, E.K. de Sousa Brandão, and E.L. Cabral. 2019. Hexasepalum nordestinum (Rubiaceae): A new species from two disjoint and fragmented areas in northeast Brazil, with a key to the American species of the genus. Syst. Bot. 44: 203-209.
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