The soil-plant interactions between serpentine and vascular plants have been well documented and serpentine is often used as a model system to understand evolution and adaptation. However, previous botanical studies often treat all serpentine as homogeneous environments ignoring the interspecific differences between serpentine formations of varying composition. As a result, little is known about how differences among serpentine soils may impact local adaptation in plants. Erysimum capitatum is a widespread soil generalist endemic to Western North America. In California, it can be found inhabiting non-serpentine soil as well as numerous serpentine soil formations across the state. Thus, E. capitatum provides the ideal system to explore the extent to which populations growing on soils derived from different serpentine formations are locally adapting to their serpentine soil of origin. The goals of this study were to: 1) Test if E. capitatum populations growing on serpentine soil are locally adapted to serpentine soil as compared to nearby non-serpentine populations and 2) Assess the extent to which E. capitatum populations experience differential success when grown in their soil of origin vs other serpentine soils. Seeds and soils were collected from four pairs of E. capitatum populations found growing on serpentine and non-serpentine soil sites along a latitudinal gradient across California and correlated with a gradient of annual precipitation. We conducted germination trials to establish if soil type impacted success and a reciprocal transplant greenhouse experiment to evaluate plant fitness across the serpentine soils. Preliminary results suggest that at least one serpentine population is better adapted to its serpentine soil of origin. These results suggest that plant adaptation to serpentine soils may be impacted by regional differences in soil characteristics and supports the need for targeted conservation efforts to protect the diversity of native plants growing on serpentine soils of varied origin.