Abstract:

The study was done to provide theoretical reference for physiological ecology and systematic development of Paeonia suffruticosa by find out the morphological characteristics of vessel. The vessel elements in stem are observed by educts of stem’s secondary xylem under bio-microscope. The Results were as follows：There are 3 types of vessel elements，that is ringed vessel，reticulated vessel and pitted vessel，the perforation plates have two types of scalarform and pitted perforation plate. The perforation on the end wall of vessel and the tip of vessel show rich variety，aperture become vestigial. There are no appearances of two states in form，the average length is 1 100 m，the average width is 200 m. Paeonia suffruticosa has stubborn adaptive mechanism of physiological ecology and complicated history of evolution.