The effects of urbanization on watershed ecosystems present a critical challenge to modern survival. Organisms in urbanized areas experience high rates of evolutionary change, but genetic adaptation alone cannot mitigate the rapid and severe effects of urbanization on biodiversity.  Highly resilient, foundation species are key to maintaining an ecosystem’s integrity. However, the rapid collapse and disappearance of watershed ecosystems calls into question the extent to which we can rely on such species for their services. Our research investigates the molecular mechanisms by which the foundation ecosystems provider, Sporobolus alterniflorus, adapts to life in an urbanized environment. To elucidate the molecular mechanisms by which Sporobolus alterniflorus copes with urbanization, we quantified cellular unfolded stress response proteins HSP70 and BiP, as well as global DNA methylation marker 5-methylcytosine (5-mC).  Specimens from two differentially impacted populations across an urban to suburban geographical transect formed the basis of this study. Grasses native to the urbanized Bronx River maintain higher baseline levels of stress response chaperone proteins (HSP70 and BiP) and exhibit a diminished unfolded protein response (UPR) when exposed to acute heat stress than their suburban Greenwich Cove conspecifics. In addition, these two differentially impacted populations exhibit inverse global DNA methylation responses when exposed to the same acute  heat stress. These findings suggest that differential stress responses represent an evolved adaptation to urbanization. We hypothesize that the phenotypic plasticity observed between these plant populations native to distinct sites is a rapid form of adaptive evolution controlled at the molecular level through epigenetics.