Miconia sect. Chaenopleura is represented in the Greater Antilles by 44 species, constituting a monophyletic group that may be diagnosed by 1) an actinomorphic androecium, i.e., the stamens forming a radially symmetrical pattern around an erect style; 2) white stamens; 3) obovate anthers, opening by longitudinal slits; 4) pale blue berries; and 5) seeds with a smooth testa. The presence of nectar, held in cup-shaped petals and likely produced by glandular hairs on the adaxial petal surface, may be an additional synapomorphy. This clade has been monographed, and phylogenetic relationships within it assessed through a cladistic analysis of 62 morphological characters. Most species belong to one of five major subclades: M. krugii--M. stenobotrys clade, M. selleana--M. subcompressa clade, M. adenocalyx--M. ferruginea clade, M. howardiana--M. favosa clade, and M. rigidissima--M. lanceolata clade; each of these is diagnosed by one to several morphological characters. Almost all species are cladospecies (4 may be metaphyletic). Miconia calycina occurs on Hispaniola, Puerto Rico, and Cuba, but the other 43 species are endemic to a single island (and often to a single mountain range). Hispaniola is most diverse (33 endemic species), followed by Cuba (4 spp.), Jamaica (3 spp.) and Puerto Rico (3 spp.). Within Hispaniola, 18 spp. (9 endemic) occur in the Cordillera Central/Massif du Nord, 12 spp. (7 endemic) occur in the Massif de la Selle/Sierra de Baoruco, 7 species (all endemic) occur in the Massif de la Hotte, and 7 spp. (1 endemic) occur in the Sierra de Neiba. The phylogenetic hypotheses suggest two dispersal events from North Hispaniola to Jamaica, and a dispersal or vicariance event separating Hispaniola and Puerto Rico. Sister species/taxa usually show geographical (ca. 17 cases) or ecological (5 cases) isolation; close relatives occasionally grow together, e.g., M. pycnoneura, M. foveolata, and M. sintenisii. There has been apparently no extinction since Ekman's time, but several species are endangered, especially in southern Haiti. Patterns of speciation and diversification will be summarized.

Key words: biogeography, Greater Antilles, Melastomataceae, Miconia, Miconieae