The medicinal part referred to is one of the nutritional organs of vascular plants, which is the underground part of the plant body developed from the embryonic root.
指药用部位是维管植物的营养器官之一,由胚根发育而来的植株体轴地下部分

When the seed germinates, the root that grows vertically into the ground is formed by the division and elongation of the embryonic root cells.
种子萌发时，由胚根细胞分裂和伸长形成的垂直向地下生长的根

Bark of the Root
根的树皮

Block-shaped root
块状的根

The roots that originate from the sheath part of the main root's interior. Their growth direction often forms a certain angle with the main root and can branch repeatedly.
由主根内部中柱鞘部位发生的根。其生长方向往往与主根成一定的角度，可反复分枝