Abstract
The Magnolia meta-population described a hundred years ago from a very limited material as Magnolia sprengeri Pamp. has been mapped and investigated over its main area of distribution in Shaanxi and Hubei of central China. These deciduous, precocious, tall mountain trees are increasingly rare due to man's need for forestry resources and marginal agricultural land. The high degree of polymorphism is discussed in terms of phenotypic plasticity, evolutionary history of early angiosperms and the status as hexaploids in a hot-spot of cyclic climatic variations and a dramatic topography. The variation in vegetative and reproductive characters is found to be much wider than previously recognised, regionally and locally. Some published species and varieties are shown to belong naturally within a variable M. sprengeri. Magnolia multiflora M.C. Wang et C.L. Min, Magnolia wufengensis L.Y. Ma et L.R. Wang and M. wufengensis var. multitepala L.Y. Ma et L.R. Wang are reduced to synonyms of M. sprengeri Pamp. M. sprengeri var. elongata (Rehder et Wilson) Johnstone is replaced with M. sprengeri var. sprengeri, while M. sprengeri var. diva (Stapf ex Dandy) Stapf is re-established for the pink (red) flowering form.
Acknowledgements
Thanks are due to Dr K.E. Flinck for continuous encouragement and financial support for the field work, also to SLU, Alnarp and the Swedish Magnolia Group for their support. The backing of this project by Prof. Jianjun Liu, NW Agriculture and Forestry University, is gratefully acknowledged. Dr Wang Yaling of Xian Botanical Garden, China, has participated in several field tours and contributed substantially in collecting work and fruitful discussions. Henrik Sjöman of SLU, Alnarp, Sweden, has taken active part in two field investigations and Ye Wei of Xian Botanical Garden has done valuable reconnaissance work. The staff members of a large number of forestry bureaus and forest farms have been most helpful and willing to share their knowledge and experiences. Numerous residents in the mountainous areas have supported us by guidance, tree-climbing and sharing valuable local information with us.