Starting from the outermost and moving towards the center, the primary tissues in an herbaceous root are arranged in this order:

• Piliferous layer: This is the outermost protective layer, also known as the epidermis, from which root hairs emerge for absorption.
• Cortex: Located just inside the epidermis, the cortex is primarily made of large parenchyma cells and is involved in storage. The innermost layer of the cortex is the endodermis, which is an important tissue in roots.
• Pericycle: This layer of cells is located just inside the endodermis and is the outermost part of the vascular cylinder (stele). Lateral roots originate from the pericycle.
• Vascular tissue: Found inside the pericycle, the vascular tissue (xylem and phloem) is responsible for transport. In roots, xylem and phloem are arranged alternately on different radii.
• Pith: This is the central region of the root, composed of parenchyma cells, and is especially well-developed in monocot roots. Dicot roots typically have a very small or absent pith.