Tallgrass prairie species often require a period of cold stratification to break seed dormancy, but not all species germinate when this occurs. Fire, which has historically played an important role in defining the prairie landscape, may also play some role in breaking dormancy by producing a variety of biologically active smoke substances. The role of smoke as a germination cue was investigated in this study, during which the ex situ germination of 37 prairie species was measured in response to aerosol smoke treatment. Overall, one third of the species responded positively, while others were either inhibited or exhibited no response at all. Smoke may therefore play a more significant role in maintaining the composition and structure of tallgrass prairie communities than was previously realized.