Prokambial

Prokambial, also spelled procambial, refers to the procambium, a primary meristematic tissue in plants. The procambium is responsible for the development of the primary vascular tissues, xylem and phloem, and thus plays a central role in primary growth of roots and stems.

Origin and location: It originates from cells of the apical meristem that are set aside during primary growth. In the embryo and in young organs, the procambium forms a strand or cylinder of meristematic tissue situated between the epidermis and cortex and the central vascular region; in stems, procambial strands usually develop into vascular bundles.

Development and function: As cells divide and differentiate, the procambial cells give rise to protoxylem and protophloem in early stages; with further development, metaxylem and metaphloem differentiate as the plant matures, establishing the primary vascular cylinder that transports water, minerals, sugars, and other solutes.

Variation and importance: The arrangement of procambial strands and the resulting vascular tissue varies among plant groups. In many dicot stems, vascular bundles form a ring; in monocots, bundles are scattered. The procambium therefore underpins primary growth and the plant’s transport system.