Since the publication of the first edition of Smartweeds to Hazelnuts in 1987, thirteen additional species and one hybrid have been discovered in Illinois. In addition, numerous nomenclatural changes have occurred for plants already known.This second edition updates the status of the Polygonaceae, Hamamelidaceae, Platanaceae, Fagaceae, Betulaceae, and Corylaceae in Illinois. Each of the newly discovered species has been added and is fully illustrated. Updated nomenclature as well as Illinois distributional data are included for each species. In addition to the fourt