medullary

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

髓部发达，髓射线明显。

2.Blood production —The marrow, located within the medullary cavity of long bones and the interstices of cancellous bone, produces blood cells in a process called haematopoiesis.

造血-髓长髓腔和松间隙内，髓通过造血作用产生血细胞。

3.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.

端分生组织中部，髓、皮层、髓射线以及叶肉这些基本组织均是由基本分生组织分化而成。根部分生组织也称为皮层原。