Biogeographic patterns of Galipeinae (Galipeeae, Rutaceae) in Brazil: Species richness and endemism at different latitudes of the Atlantic Forest "hotspot"

The subtribe Galipeinae (Rutaceae) is a flowering plant group endemic to the Neotropical region, with its center of diversity in the Brazilian Atlantic Forest. Here, we aim to describe and analyze the distribution patterns of the group in Brazil, in search for possible areas of endemism. We then discuss our results to contribute to the debate on the Atlantic Forest history and endemism patterns. Our research relies on an updated database from herbarium collections and expert points, including taxonomic validation and georeferencing procedures. We performed both Parsimony and Endemicity analysis (PAE and NDM, respectively) and evaluated the contribution of narrowly distributed and widespread species to the overall pattern, testing if they are unevenly distributed at different latitudes of the Atlantic Forest. We recovered areas of endemism already found in other studies using other groups as study model. We identified five areas at different latitudes, according to PAE analysis: four in the Atlantic Forest, between Bahia and Rio de Janeiro states, and one in the Amazon. The latter area was not recovered by NDM analysis and we discuss that this is actually an artifact of PAE analysis due to collection bias. Although the widespread species have contributed more than the narrowly distributed ones for the overall pattern, the distribution of the group is more explained by species of medium-range distribution. We discuss our results considering current models based on historical events as Quaternary refugia forest and alternative hypothesis of vicariance.