Plants

Table of Contents

1. Stoma

The pore on the surface of leaves used for

2. Lignin

The cellulose is not strong enough to sustain the height of a tree. Lignin fills inbetween the cells to fortify the structure.

3. Cambium

The outer layer of the trunk underneath the bark. These are the only living part that is few milimeters thick.

Xylem cells on the inside produces lignin and dies. Leaving out various strutures such as tracheids, vessels, and fibers.

The old xylem cells at the core are filled with resin to form dense heartwood. The yet functioning part around it is called the sapwood.

3.1. Phloem

These are the cells in the cambium that grows outward. They become one of the three:

  • sieve cells: the trasport tunnel
  • companion cells: the signaling agent
  • parenchyma: store energy, repair damage, kill intruders

3.2. Phellogen

  • Cork Cambium

The outermost cambium that grows outward to produce the bark.

4. Phellem

  • Cork, Bark

5. References

Author: Jeemin Kim

Created: 2026-07-12 Sun 14:28