Taxonomic implications of fruit morphology in chinese species of the genus Bupleurum L. (Apiaceae)

Background: Because of the certain overlapping of the genus Bupleurum, the identification features are few and the delimitation among species is difficult, Bupleurum taxonomy is under frequent revisions. In this research, hierarchical cluster analysis based on morphology characters is done to establish a dendrogram and illustrate the taxonomic relationship among Bupleurum species (Apiaceae) from China. Materials and Methods: The fruit morphology of 17 Bupleurum taxa from China was investigated with a scanning electron microscope (SEM) and optical microscopy (OM). The hierarchical cluster analysis based on 41 morphological character states belonging to 9 characters was done to establish a dendrogram and illustrate the taxonomic relationship among the studied species of Bupleurum (Apiaceae) from China. Results: Based on fruit morphological characteristics, it is possible to separate the Bupleurum species into the following four groups. The research indicates that the classification of Bupleurum in China is closely related to geographical distribution, which is divided into Southwestern and Northeastern Bupleurum. Conclusion: The fruit morphological characteristics are variable enough to distinguish species between Bupleurum, such as fruit length, width, shape, colour, the curvature of the outer periclinal and so on in this article. Morphological characters could be probably the taxonomical standard of intraspecific and interspecific delamination, which is significant for understanding the classification of Bupleurum.