Collateral or bicollateral vascular bundle, developmental pith and medullary ray are obvious.

髓发达，髓射。

Ground meristem The central region of the apical meristem from which the ground tissues of pith, cortex, medullary rays, and mesophyll differentiate. In root meristem it is also called periblem.

位于顶端分生组织的中，髓、皮层、髓射以及叶肉本组织均是由本分生组织分化而成。根分生组织也称为皮层原。