Study on intraspecific variation of Vitex rotundifolia growed in China with numerical taxonomy method Characterication of construction and functions of Vitex rotundifolia var.simplicifolia community during the process of desertification in Poyang Lake Population Genetic Structure of the Medicinal Plant Vitex rotundifolia in China: Implications for its Use and Conservation Hemianatropous Ovule and Allium Type Embryo-sac of Vitex rotundifolia(Lamiaceae)