ABSTRACT
The root of Bupleurum is covered by periderm composed of five to ten regularly arranged cork cell layers of quadrangular cells elongated periclinally. The stems of most species in Bupleurum genus are ribbed in surface. The stem is covered with one layer of epidermal cells, the outer tangential wall of which are slightly thicker and covered by cuticle. The leaf blade is thin, covered by epidermis and cuticle. The leaves of Bupleurum are bifacial, usually with one layer of palisade parenchyma and five to eight cell layers of spongy parenchyma. The number of oil ducts at the vallecula and commissure in the cremocarp is used in the classification of Bupleurum genus. In the aerial parts, ribs and pith cavity of stems, fibers of leaves, and the numbers of oil ducts at vallecula in the cremocarps can be used for classification and identification purposes.
