Britannica
Sources used in this answer
How does cork cambium contribute to bark formation?
Created from Britannica articles
using AI.
AI can make mistakes, so verify using Britannica articles.
plant development
The life cycle of the fern. (1) Clusters (sori) of sporangia (spore cases) grow on the undersurface of mature fern leaves. (2) Released from its spore case, the haploid spore is carried to the ground, where it germinates into a tiny, usually heart-shaped, gametophyte (gamete-producing structure), anchored to the ground by rhizoids (rootlike projections). (3) Under moist conditions, mature sperm are released from the antheridia and swim to the egg-producing archegonia that have formed on the gametophyte's lower surface. (4) When fertilization occurs, a zygote forms and develops into an embryo within the archegonium. (5) The embryo eventually grows larger than the gametophyte and becomes a sporophyte.
In the context of plant development, the cork cambiumâalso known as the phellogenâis a lateral meristem essential for the formation of bark in woody plants.21
As a plant increases in girth through secondary growth, the original epidermis cannot expand and is eventually destroyed. The cork cambium replaces this protective layer by producing cork cells toward the outside and parenchyma cells (phelloderm) toward the inside. Together, these tissues form the [periderm].2
The cork cambium contributes to bark formation through the following processes:
- Protective Barrier: The cork cells produced by the cambium become nonliving at maturity and are lined with suberin, a fatty, waterproof substance that protects the plant from desiccation and environmental stress.21
- Continuous Renewal: Because the outer bark cannot accommodate the increasing diameter of the stem, it is shed over time. To maintain protection, new cork cambiums periodically arise in the secondary phloem, creating successive layers of periderm.23
- Bark Composition: Bark is defined as all tissues outside the vascular cambium. The cork cambium is responsible for generating the outer bark, which consists of these dead cork cells and old, crushed phloem.21