Abstract
The Rutaceae genera Nycticalanthus (monotypic) and Spiranthera (4 species), morphologically similar, have restrict distribution to South America. Both genera are characterized by trifoliate leaves, very aromatic flowers with gynophore and schizocarpic fruits with follicular mericarps. Among the Spiranthera species, S. odoratissima has the larger distribution, the major phenotypic plastici…