Peonies Rockii (Paeonia SUFFRUTICOSA Andr. Var. PAPAVERACEA (ANDR.) Kerner) are deciduous shrubs of the genus Ranunculaceae, with stems up to 2 meters tall and short, thick branches. The leaves are bipinnately compound, and the leaflets are undivided. Flowers Solitary; shoot apices, 10-17 cm in Diam. ; Pedicel 4-6 cm long; base of inner surface of petals with dark purple patches, obovate, apex irregularly undulate; Disk Leathery, cup-shaped, purplish red, apex with several sharp teeth or lobes completely enveloping carpels, dehiscence at carpel maturity. The pods were oblong and densely yellowish-brown hispid.
Distributed in northern Sichuan, southern Gansu, southern Shaanxi (Taibai Mountains) . In Gansu, Qinghai and other places have cultivation. It grows in undergrowth thickets on hillsides at elevations of 1100-2800 M.
Paeonia Rockii grows in undergrowth thickets on hillsides between 1100 and 2800 meters above sea level. Cold Tolerance, drought tolerance, strong adaptability. The main production area is in the temperate zone, the ground spans the semi-arid, the semi-humid area. The annual average temperature is 5-12 °C, the extreme minimum temperature-29.6 °c (Lintao) , the accumulated temperature ≥10 °C is 1584.2-3824.8 °C, and the annual precipitation is 300-600 mm. According to the introduction situation, some varieties of Paeonia Rockii could overwinter normally in Shangzhi with an annual mean temperature of 2.3 °C and an absolute minimum temperature of-44.1 °C. Paeonia ROCKII prefers light and tolerates half shade. It is suitable for all kinds of soils developed on Loess Parent Material and slightly alkali-resistant (Ph 8.0-8.5) . Its ecological type belongs to plateau cool and dry ecological type.
Paeonia rockii is a widely distributed species in the wild. The cultivated paeonia rockii in the middle of Gansu Province and its adjacent areas evolved from this species. Because the central part of Gansu Province is the main production area, it is also called Gansu variety group, later renamed as Northwest Variety Group. These varieties are characterized by distinct color spots at the base of the petals, fragrant flowers, cold and drought resistance, adaptability, in the three North regions of China has a good development prospects, in the international market is also very popular. Now there are more than 300 varieties, which is the second largest variety group of Chinese peony.
paeonia rockii is not only an ornamental plant but also an important medicinal plant. Its root bark for medicinal, also known as Paeonia Suffruticosa, cooling blood, promoting blood stasis, and for pain, Tongjing Medicine. It is of certain significance to study the phylogeny of the genus Paeonia and to cultivate new varieties of Paeonia