Myrcia section Aulomyrcia includes approximately 120 species that are endemic to the Neotropics and disjunctly distributed in the moist Amazon and Atlantic coastal forests of Brazil. Staggemeier et al. examine one nuclear and four plastid markers to produce a phylogeny that supports the need to unite taxonomically the two traditional genera Myrcia and Marlierea in an expanded Myrcia s.l. Relationships are found suggesting links between the Amazonian and Atlantic forests. Evidence is also presented that the lowest extinction rates are found inside refugia and that range expansion from unstable areas contributes to the highest levels of plant diversity in the Bahian refuge.