Intraspecific Variation of Leaf Epidermal Cuticle Waxes under Scanning Electronic Microscope:Stipa purpurea and Oxytropis microphylla from the QinghaiTibet Plateau Effect of Soil Water Deficit and High Temperature on Leaf Cuticular Waxes and Physiological Indices in Alfalfa (Medicago sativa) Leaf Effect of soil water deficit and enhanced ultraviolet radiation on contents and crystal structure of cuticular waxes in alfalfa (Medicago sativa) leaf The Ultra-Morphology and Chemical Composition of Waxes Secreted by a Scale Insect Physokermes shanxiensis (Homoptera : Coccidae)