Closely related plant species frequently co-occur and overlap in ecological characters. This overlap may lead to resource competition (i.e., for pollinators) and result in character displacement (i.e., divergence in floral phenotype or phenology) or reproductive interference (i.e., hybridization). Shared ecological characters may, on the other hand, also promote facilitation among co-occurring species and increase reproductive success. We use the North American plant genus Rhexia (Melastomataceae) as model to test whether co-flowering species share pollinators and whether co-flowering leads to subtle divergence in floral phenotypic traits as expected when flowers compete for pollinators. Rhexia further presents a functionally highly specialized pollination system, buzz-pollination, where pollen may only be released from flowers when specific vibrations are applied. Bees are the only major group of pollinators capable of producing such vibrations, but to date, we know little about how the niche of buzzing bee pollinators is partitioned. From preliminary field studies in Florida, the genus’ diversity hotspot, we know that Rhexia share pollinators, and largely overlap in floral trait space. Subtle temporal differences in activity patterns of different bee species may contribute to reproductive isolation, as well as differences in floral traits mediating fit with pollinators. We will draw references to first insights into buzz-pollination niche partitioning also from tropical Melastomataceae communities, where the family is most diverse in terms of species richess and floral disparity.