韧皮部

The micrib belonging to bicollateral bundle is well developed.The bundle sheath is composed of idioblasts.

主脉达，有异细胞组成的维管束鞘，具双皮。

Plenty of laticiferous tubes were included in roots, stems and leaves.Intraxylary phloem formed around the pith.

髓的外围形成一环皮，这些结构特征使罗布麻能更好的适应干旱、盐碱等恶劣环境。

Actinostele A rype of protostele in which the xylem is star shaped and the phloem lies between the points of the star.

原中的一种类型。木质是星形的，皮位于星形之间。

These cells began to devise, then developed into aloin cells through enlargement of volume and vacuolization with the differentiation of metaphloem and metaxylem.

在后皮和木质成熟过程中，这些细胞体积逐渐增大，并液泡化，成为大型薄壁细胞（芦荟素细胞），位于筛管外侧。