Fixed root: The location of occurrence is determined.

Adventitious roots: Roots arising from the stems, leaves, old roots and hypocotyl of the plant. The resulting location is uncertain

Tap root system: It is composed of the main root and lateral roots, but the appearance of the main root is strongly developed, which is different from the main root in terms of thickness and length.

Fibrous root system: The entire root system is mainly composed of adventitious roots and lateral roots

Outer cortex: The innermost layer of cells in the cortex, arranged neatly and tightly without intercellular gaps

Endothelial layer: The outermost one to several layers of cells in some plant cortex are tightly arranged with no intercellular spaces and are called outer cortex.

Cortical parenchyma cells: composed of multiple layers of parenchyma tissue, accounting for a large proportion of young roots. The cells are loosely arranged, with obvious intercellular spaces. The cells often contain starch granules and other post-containing substances.

pericycle: originates from the procambium

Primary xylem: located in the center of the root, mainly composed of vessels and tracheids

Primary phloem: distributed between the radial angles of primary xylem

Parenchyma cells: between primary xylem and primary phloem