Dry Matter Accumulation and Polysaccharides Distribution in Different Sections of Perennial Huang-jing (Polygonatum sibiricum Red. ) Advances in studies on chemical constituents of three medicinal plants from Polygonatum Mill. and their pharmacological activities Seed Dormant Characteristics of Polygonatum sibiricum Red. Polysaccharides from Polygonatum sibiricum and their immunological activities