XVI International Botanical Congess

Research shows that the chromosome numbers known from both genera Hilliella and Yinshania are quite different. Four species of Yinshania have a diploid number of 2n=12(14), are based on x=6, while five species of Hilliella have higher chromosome number, 2n=42(44), are based on x=7. We found that the chromosome numbers or the base numbers of both genera are closely relative to their generic morphology respectively. Hilliella seeds are sized 1-2.5 x 0.8-1.5 mm and with dense minute tubecles on the testa surface, while Yinshania seeds are sized 0.5-1 x 0.5-0.8 mm and with reticulation on that. The septum of fruit in Hilliella is absent, while in Yinshania it is complete or perforated. Besides above characters, in Hilliella all the species have compound leaves, except for H. Sinuata which usually have simple leaves, while in Yinshania, with few exceptions, most species have pinnatisect or pinnatipartite leaves. Recently, the studies on micromorphological characteristics of epidermal features of leaves clearly show the differences between Hilliella and Yinshania. We consider all above proofs are enough to support the point of view that the two genera should be maintained.