while the nothospecies remained in refugia to the South of Europe. During their retreat P. lactiflora and P. mairei likely became sympatric and so produced the Himalayan nothospecies P. emodi and P. sterniana.
It is likely that the parent species occurred in the same region when the hybrids arose, and were later exterminated by successive Pleistocene glaciations,
The large distance between the ranges of the parent species and the nothospecies suggest that hybridisation already occurred relatively long ago.
Genetic analysis has shown that all Mediterranean species are either diploid or tetraploid hybrids that resulted from the crossbreeding of species currently limited to eastern Asia.
The species of the section Paeonia have a disjunct distribution, with most of the species occurring in the Mediterranean, while many others occur in eastern Asia.
while P. obovata grows in warm-temperate to cold China, including Manchuria, Korea, Japan, Far Eastern Russia (Primorsky Krai) and on Sakhalin, and P. lactiflora occurs in Northern China, including Manchuria, Japan, Korea, Mongolia, Russia (Far East and Siberia).
P. veitchii grows in Central China (Qinghai, Ningxia, Gansu, Shaanxi, Shanxi, Sichuan and the eastern rim of Tibet), like P. mairei (Gansu, Guizhou, Hubei, Shaanxi, Sichuan, and Yunnan),
Paeonia emodi occurs in the western Himalayas between Pakistan and western Nepal, P. sterniana is an endemic of southeastern Tibet,
Between the two concentrations, the subspecies of Paeonia daurica occur, with subspecies velebitensis in Croatia, and daurica in the Balkans and Crimea, while the other subspecies coriifolia, macrophylla, mlokosewitschii, tomentosa and wittmanniana are known from the Caucasus, Kaçkar and Alborz Mountains.
