The comparison of gene flow and Gst (Table 6), and the correlation between the Nei’s genetic and geographical distances (r = 0.77, p < 0.01) among populations shows that A. flaccida populations follow the isolation-by-distance model. The estimated gene flow for a species may describe a migratory pattern of individuals occurring from the distant past to the present , and the data observed here should not be interpreted by considering only the current state of isolation in A. flaccida populations.