Sympatric speciation is not commonly recognized as one of the more important modes of speciation. This may be due to the slow rate of evolution in this mode as well as its often cryptic nature. Pollinators and small micro-ecological differences are likely important drivers of sympatric evolution. Importantly in plants, pollinators can have a significant impact on breeding between different individuals even when they are growing close together. This discrimination of pollinators is driven by a variety of morphological traits in a plant, thereby possibly leading specific pollinators to have a strong plant preference. In addition small ecological differences related to phenological cycles may create a feedback loop further altering pollinator preference.  In Western North America, Ericameria nauseosa (Asteraceae)  is a common shrub with over 20 named varieties that co-exist and may exchange genes. Despite their interbreeding, these varieties often appear as, seemingly, stable evolutionary units. In this study we ask: 1) Do pollinators discriminate between varieties of E. nauseosa? 2) What maintains the differences between E. nauseosa varieties when growing in sympatry?  We completed a series of experiments comparing different varieties for; viability of seeds, morphological floral measurements, identification of insect communities, and observational field trials with fluorescent pigment as a proxy for gene flow.  Green varieties had a 36% germination rate compared with the gray varieties that had a 12%  germination rate. The gray varieties g erminated 1.7 times faster than the green. There were differences in floral morphological measurements of the corolla and anther lengths with the gray variety having 1.3 times the length of the green. Pollinator communities also differed with the green varieties having more species in the Hymenoptera and Diptera orders with species in the Lepidoptera and Hemiptera orders dominating the gray varieties. Lastly, pollen flow among all sites typically were between green varieties to gray as well as green varieties to green  and gray varieties to gray, but not from gray varieties to green. Preliminary data suggests that due to floral morphological differences, these varieties of E. nauseosa have different pollinator communities. These pollination traits are likely further enhanced by variation in seed germination that contribute to different phenology. Thereby, providing evidence of pollinator impact on speciation events through gene flow. This study provides an understanding of the ongoing diversification events in E. nauseosa.