Flare tree peonies (Paeonia rockii hybrids) and the origin of the cultivar group.

摘要

Flare tree peonies (FTP, P. rockii hybrids), known as Ziban Mudan in Chinese and named for an obvious flare at the petal base of every cultivar, are very distinct from common tree peonies (CTP, P. x suffruticosa cultivars) both in biology and in ornamental use. They have a very long cultivation in Northwest China but were included in CTP until recently being identified as a special cultivar group. The biological characters of FTP and the origin and composition of the cultivar group are summarized in this paper: (1) FTP are superior to CTP for landscape, horticulture and breeding to some extent because of their fragrance, up-standing flowers held above the leaves, vigorous growth and wide adaptability to cold and dry environments, tolerance to saline-alkali and lean soils, and disease and pest resistance. (2) The group of FTP, composed of original, traditional and modern cultivars, is also polyphyletic in origin, just as are CTP. Its cultivars are mainly and directly originated from species P. rockii and indirectly affected by P. jishanensis and P. ostii through cultivars of CTP.