Pleroma
In botany, the developing meristematic central cylinder of the root is referred to as the pleroma (Greek pleroma : "filling") .
- In the case of dicotyledons , there are three so-called initial deposits in the development of the roots : the first supplies cells to the pleroma, the second to the periblem , which later differentiates into the cortex, and the third to the dermatocalyptrogen from which rhizodermis and calyptra emerge.
- In the case of monocotyledons , the bark and rhizodermis emerge from an initial insert, the calyptra has its own initials in the apex.
- In gymnosperms only the pleroma has discrete initials, all other components of the root arise from a relatively undifferentiated initial complex at the tip of the root.