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

发达，射线明显。

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，、、射线以及叶肉这些基本组均是由基本分生组分化而成。根分生组也称为原。