HONG De-Yuan’s three-volume monograph of the popular genus Paeonia is a comprehensive taxonomic revision, based on extensive field observations, population sampling, examination of more than 5,000 specimens, and multidisciplinary study. This final volume in the series focusses on the biology, phylogeny and evolution of Paeonia, illustrated with over 200 photographs, line drawings and maps. This is an essential reference for taxonomists, growers, breeders, horticulturalists and general biologists.