Notes on Yulania Spach

In this paper, author introduces the history of classification of Yulania Spach, compares the difference between Yulania and Magnolia, dissertates the evolution of powder chamber dehisce on side→extrorse or introrse, flower after leaves→flower before leaves and flower bud acrogenous→axillary→cyme, and presents some new opinions such as that Yulania and Magnolia are two converged genera, flower before leaves is the sign of Yulania, and the origin, distribution and diversity center of Yulania is China. To affirm the genus Yulania can effectively settle the disputed of the system of Magnolia L. and Magnoliaceae.