protostele

protostele

1. medulated protostele

具髓原生中柱

2. Haplostele A type of protostele having a solid strand of stele with the xylem on the inside encircled by phloem, pericycle, and endodermis.

单中柱：原生中柱的一种类型，是由韧皮部、中柱鞘和内皮层包围着内方的木质部构成的实心中柱。

3. Protostele A simple form of stele, uninterrupted by leaf gaps, consisting of xylem in the center completely surrounded by phloem.

原生中柱：中柱的一种简单类型。

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

星状中柱：原生中柱的一种类型。木质部是星形的，韧皮部位于星形之间。

5. Stellar arrangements vary considerably in plants from the simple protostele, in which leaf gaps are absent, to the complex dictyostele, in which there are many closely spaced LEAF GAPS.

根部的中柱有一个维管组织的中央核心，用以对抗拉应力。