Systematics, taxonomy and floristics of Brazilian Rubiaceae: an overview about the current status and future challenges

the rubiaceae is the fourth angiosperm family in number of species in the world and in the neotropics. its overwhelming diversity and presence in most biomes, and at most vegetation layers, makes this family one of the most important components of tropical vegetation. during the last two decades, family classification went through several reorganizations, mostly influenced by the advent of molecular phylogenetic studies, and many taxonomic revisions and floristic studies on brazilian rubiaceae have become available. in view of the considerable amount of literature that has recently been produced on neotropical rubiaceae, the present work has two main objectives: the first is to offer an overall view of the most recent family classification with emphasis on the genera of rubiaceae occurring in brazil, and to indicate particular taxa that are still in need of phylogenetic and taxonomic studies; the second objective is to present a short discussion on the state of floristic and taxonomic knowledge with respect to the various regions of brazil, indicating the taxa and the geographic areas that need to be studied.