The genus Paeonia is divided into three sections, Paeonia, Moutan and Onaepia. Paeonia is the largest section of the genus
and is comprised of approximately 28 herbaceous species native to China and/or Europe. Onaepia is the smallest section containing
only two herbaceous species that are native to the western United States. Section Moutan contains approximately 8 species,
all of which are woody shrubs that are generally referred to as tree peonies, although they rarely if ever exceed 6-8 feet
in height. It would be more appropriate to refer to these plants as shrub peonies since they are only slightly taller than
their herbaceous cousins. These magnificent flowering shrubs are native to China where they have been revearded for centuries.
Hybrid peonies can also be divided into three main catagories; 1) Herbaceous hybrids, 2) Tree peony or shrub peony hybrids
and 3) Intersectional hybrids. Each of these types will be discussed briefly below.