Photosynthetic and Physiological Characteristics of Three Shrubs Species in Shell Islands of Yellow River Delta Advances in studies on chemical constituents from Cortex Periplocae and its pharmacological effects Effects of the crude extracts from Periploca sepium Bunge on the bioactivity of imported cabbage worm, Pieris rapae Response of Gas Exchange Parameters of Periploca sepium Bunge to Soil Water Content in Loess Plateau Light Response of Periploca sepium Bunge Leaves Physiological Parameters under Salt Stress