The absence of convincingly delimited monophyletic groups within the Miconieae is well known to students of the family. The current revision of Charianthus represents the first genus in the Miconieae to be the subject of a molecular cladistic analysis. Molecular data was combined with morphology to analyze hypotheses of phylogeny within Charianthus using nine additional species as outgroups. The internal transcribed spacer (ITS) region of 18S 26S nuclear ribosomal DNA was sequenced and provided important insights into the evolutionary relationships of the taxa under investigation. Each cladistic analysis supports the monophyly of Charianthus when C. fadyenii is excluded. A combined analysis of the morphological and molecular data sets resulted in a strongly supported Charianthus clade with 100% bootstrap and a decay value of 12. Charianthus fadyenii is in the Tetrazygia clade where its position as sister to T. bicolor is supported by a bootsrap value of 89% and decay of three. Inclusion of C. fadyenii in Charianthus makes both Charianthus and Tetrazygia non-monophyletic, therefore, this species is transferred to Tetrazygia. Morphological adaptations to hummingbird pollination have arisen independently in both Charianthus and Tetrazygia. Charianthus purpureus, as defined by previous taxonomists, is a polyphyletic species because of the inclusion of the populations on the islands of Dominica and Grenada, thus, two new species must be recognized. Charianthus is a morphologically well-characterized clade of six species of hummingbird pollinated shrubs and small trees found in the tropical montane rain forests and elfin forests of the Lesser Antilles. The revised circumscription of the group makes it the only plant genus endemic to the Lesser Antilles. Ongoing studies will continue to concentrate on the implementation of a phylogeny based on sequence data of both a nuclear gene (ITS) and a chloroplast gene (trnL-F, matK, or GBSSI) for all genera of Miconieae.

Key words: Charianthus, ITS, Lesser Antilles, Melastomataceae, Miconieae, morphology