Ultrastructural Studies on Development of Endosperm in Plantago major L. Karyotypes and C-values of Two Plantago Species from the QinghaiTibet Plateau, China Determination of Ursolic Acid and Oleanolic Acid in Asiatic Plantain (Plantago asiatica) by HPLC Cytoembryological Studies in the Development of Endosperm and Embryo in Plantago major L. Effects of Altitude on Antioxidative System in Leaves and Roots of Plantago major Cytoembryological Studies in the Development of Endosperm and Embryo in Plantago major L. Ultrastructural Studies on the Development of Zygote and Proembryo in Plantago major Karyotypes and C-values of Two Plantago Species from the QinghaiTibet Plateau, China Ultrastructural Studies on the Development of Zygote and Proembryo in Plantago major