Fig. 2.
Anatomical structure of P. notoginseng taproots at different developmental stages. a March. b-e May to August. f, g October–November. Avc, accessory cambium. Co, cortex. Ep, epidermis. Ppc, phloem parenchyma cell. Pph, primary phloem. Px, primary xylem. Sph, secondary phloem. Sx, secondary xylem. Vc, vascular cambium