The taxonomical history of the woody group(peonies) in the genus Paeonia is re-
viewed in the present paper. The group is endemic to China, but Paeonia suffruticosa is
commonly cultivated throughout the north temperate region and has long been known as “the
King of Flowers” in China. However, the taxonomy of the group had been neglected before
the 1990' s. Since 1990, a number of new species and subspecies have been published. With
the support from the National Geographic Society, the senior author of the present paper and
his coworkers have made expeditions to all parts of the distribution area of the group, visited
all the type localities and sampled a total of 64 populations. Based on the character analysis
and examination of the type specimens or photos, each taxon is reviewed with its name
checked nomenclaturally, and finally the taxonomy of the whole group is revised. As a re-
sult, eight species, three of which each contains two subspecies, are recognized. They are
Paeonia suffruticosa Andrews subsp. suffruticosa and subsp. yinpingmudan D. Y.
Hong, K. Y. Pan et Z. W. Xie, P. jishanensis T. Hong et W. Z. Zhao, P. qiui Y. L.
Pei et D. Y. Hong, P. ostii T. Hong et J. X. Zhang, P. rockii (S. G. Haw et L. A.
Lauener )T. Hong et J. J. Li subsp. rockii and subsp. taibaishanica D. Y. Hong, P. de-
composita Hand.-Mazz. Subsp. decomposita and subsp. rotundiloba D. Y. Hong, P.
delavayi Franeh. and P. ludlowii (Stern et Taylor)D. Y. Hong. P. baokangensis Z. L.
Dai et T. Hong and P. yananensis T. Hong et M. R. Li are considered as hybrids between
P. rockii and P. qiui and between P. rockii and P. jishanensis respectively. In addition,
the reduction of a number of names recently published to synonyms is explained.
