Patterns of Diversification of Miconia (Miconieae) in the Greater and Lesser Antilles

Abstract

Miconieae are the largest tribe in the family Melastomataceae with ca. 1900 described species. The Greater and Lesser Antilles harbor an impressive number of species from the Miconieae, which occur throughout the islands. Four major clades of Miconia are represented in the Antilles, the Caribbean, Chaenopleura, Mecranium, and Sagraea clades, corresponding to five in situ radiations. The Caribbean clade consists of ca. 160 spp., the Chaenopleura clade (= Miconia sect. Chaenopleura) of ca. 55 spp., Mecranium clade (= Miconia sect. Sagraeoides) of ca. 25 spp., and the Sagraea clade (= Miconia sect. Sagraea) of ca. 45 endemic spp. and is represented by two separate radiations in the Antilles. Likewise, numerous widespread continental species (ca. 45) from disparate subclades across Miconieae occur throughout the islands (presumably originating from many long-distance dispersal events), further increasing the Melastome diversity there. Each of these major clades is briefly characterized, and the evolutionary/phylogenetic patterns within each are discussed. Based on a phylogenetic framework, we discuss the patterns of diversification among the islands, as well as some of the biogeographic patterns of these fascinating radiations within the islands. We incorporate known data regarding ecological pressures and morphological evolution that likely have aided the diversification of this clade principally throughout the mountainous areas of the islands. Three new combinations are made in Miconia for Mecranium integrifolium, Miconia neibensis (Skean) Skean, Judd and Majure, comb. nov., Miconia neibensis subsp. alainii Skean, comb. nov., and Miconia neibensis subsp. integrifolia Skean, comb. nov.