Little is known about environmental drivers of hybridization, but its phylogenetic distribution across plants is heterogeneous, suggesting that plant traits may play an important role. Conservatism of biotic niche could explain why some plants are prone to hybridization, as conserved pollination strategies would lead to a lack of pollinator assemblage divergence and therefore opportunities for gene flow, although this hypothesis has yet to be tested. The taxonomic tribe Heuchereae (Saxifragaceae) is a well-characterized system for pollinator interactions and particularly for floral scent, the primary pollinator attractant in the group. Floral volatile organic compounds (VOCs) in this clade, characterized to date only in Asimitellaria and Lithophragma, are hypervariable at the population level and are thought to be responsible for pollination selectivity, leading to divergent pollinator assemblages. High levels of interspecific pollinator attractant divergence may be therefore responsible for the relatively low levels of hybridization observed in these groups. Heuchera flowers, by contrast, are thought to be pollination generalists and Heuchera species accordingly hybridize frequently. While floral volatiles have yet to be characterized for Heuchera, understanding variation in pollinator attractants would offer insight into whether the diversity of prezygotic isolation mechanisms across a recent radiation are predictive of hybridization rate.      Given that pollinator-mediated gene flow primarily hinges on VOCs in the relatives of Heuchera, we investigated whether high rates of hybridization observed in Heuchera may be associated with low interspecific divergence of VOCs, using as a system the hybrid zone between H. americana and H. richardsonii in the midwestern US. We optimized a closed-space collection and GC-MS (gas chromatography-mass spectrometry) protocol to characterize VOCs in Heuchera flowers. To identify floral visitation and effective pollinators, we conducted pollination observations at 47 different populations across the eastern United States, ranging from Arkansas to North Carolina, north to Minnesota, over the span of two years. GC-MS data from ~110 Heuchera representing 21 populations suggests that shared classes of VOCs, and to some extent individual compounds, are shared within the hybrid complex while other Heuchera that do not hybridize with these species have distinct species-specific compounds. Pollination observations confirm shared effective pollinators and the importance of VOCs in determining floral visitation in Heuchera.