Abstract
Callicarpa japonica (Lamiaceae) is a morphologically variable shrub widely distributed throughout Japan. In this study, we investigated the intraspecific genetic structure and geographical distribution pattern of the morphological variations. A border of genetic variation in the chloroplast DNA and nuclear rDNA ITS regions between eastern and western Japanese populations was recognized in the Kinki area. Leaf size and thickness varied continuously and the observed pattern of morphological variation was not coincident with genetic differentiation. Moreover, plants with large and/or thick leaves were found in both the eastern and western populations, indicating that they were not monophyletic.
