Judd, W. S., Skean, J. D., Jr., Bécquer, E. R., & Majure, L. C. (2014). Taxonomic studies in the Miconieae (Melastomataceae). XII. Revision of Miconia sect. Miconiastrum, with emphasis on the Miconia bicolor complex. Journal of the Botanical Research Institute of Texas, 8(2), 457-491.
Abstract: A new section, Miconia sect. Miconiastrum, is recognized (and includes species previously placed in Calycogonium, Charianthus, Miconia, and Tetrazygia). Within this clade, the species of the Miconia bicolor complex are revised. For the nine species of the M. bicolor complex, descriptions, nomenclatural information (including four new names: Miconia karsticola, M. guajaibonensis, M. cajalbanensis, and M. maestrensis), specimen citations, and eco-geographical characterizations are presented, along with an identification key to members of the section. Miconia sect. Miconiastrum represents a monophyletic group within the Caribbean clade of tribe Miconieae (Melastomataceae) and the group is restricted to southern Florida, the Bahamas, Cuba, and Hispaniola. The clade is characterized by hypanthia strongly constricted in fruit, more or less reduced calyx teeth, obovate to spathulate petals, stamens dropping before the petals abscise, and leaves with globularstellate to stellate hairs or peltate scales on the abaxial surface. Most species possess mite domatia formed from a dense tuft of elongate, multicellular, barbate, eglandular hairs in the axils of the midvein and major secondary veins, and they have seeds with smooth to slightly bulging testa cells. Within sect. Miconiastrum a large subclade, i.e., the M. bicolor complex, is diagnosed by 5- or less commonly 6-merous flowers with the petals abaxially papillose-granulose. All members of this clade, except for M. karsticola, also possess paniculate-cymose inflorescences of numerous flowers and abaxial leaf surfaces usually densely covered with well-developed stellate hairs or peltate scales. Within the M. bicolor complex, indumentum characters (as observed on the abaxial leaf surface), form of the calyx tube, size of the calyx lobes, and presence/absence of mite domatia are taxonomically significant.