This chapter will highlight a series of lithographs produced by Franz Unger and Josef Kuwasseg that emphasize how Unger used plants to represent different periods of earth history. While Henry De la Beche is credited with the first depiction of ancient life through art (Duria antiquior), Unger’s work was the first to illustrate how plants could be used as indicators of changes in life history. In collaboration with artist Josef Kuwasseg, he embarked on a project entitled The Primitive World in Its Different Periods of Formation that consisted of 14 lithographs that were published in 1851. The title was unique in that it combined the concepts of a “primitive world,” or the widely accepted contemporary idea of undifferentiated deep time, with our modern concept of different periods of earth history. Unger selected periods for this project based upon major strata, but his botanical roots led him to emphasize the importance of plants in each lithograph. The series begins with the “Transition Period,” or the strata that contain the most fossil evidence to develop a reconstruction, and ends with a depiction of the arrival of man in a plant-filled world. This series of lithographs offers a unique contribution to the history and philosophy of geology as Unger recognized the importance of plants to our understanding of geology and deep time in the nineteenth century.