Abstract: This paper deals with the morphological and cytological variation in various forms of P. odoratum complex. A quantitative analysis on the correlation between some diagnostic characteristics was also made with pictorialized scatter diagram and histogram. The results show that the presence or absence of angles on stems is closely correlated with smooth or verrucate lower surface of leaves and the position of stamens (above or below the middle). With chromosome numbers, they heve 2n=18 and 2n=20 respectively. It is suggested to treat them as two distinct species and restore P. simizui Kitag as species status.

Key words: P.odoratum, Mophological variation, Karyotype, Taxonomy