Piptocarpha axillaris (Less.) Baker is an endemic plant of Brazil, being in Paraná state the most abundant species of the genus. The scarcity of studies on the species motivated the development of this book, which had as main objective to perform morphoanatomical, phytochemical, preliminary in vitro toxicity and antioxidant activities of the extract and fractions from aerial parts of that species. After evaluation of the results presented in the tests it was observed that the species has low toxicity and promising antioxidant activity.