Cortex

Definition

The cortex is the outermost layer of a lichen's thallus, providing protection and structural support. It is typically composed of tightly packed fungal hyphae.

5 Must Know Facts For Your Next Test

1. The cortex serves as a protective barrier against environmental stress such as desiccation and UV radiation.
2. It is primarily made up of fungal cells, which are often pigmented to protect against sunlight.
3. The cortex can vary in thickness depending on the species of lichen and its environment.
4. Underneath the cortex lies the algal layer, where photosynthesis occurs.
5. The integrity and composition of the cortex are crucial for the overall health and functionality of the lichen.

Review Questions

• What is the primary function of the cortex in lichens?
• How does the composition of the cortex contribute to its protective role?
• What lies directly beneath the cortex in a lichen's structure?

Related terms

Thallus:

The body of a lichen, consisting of layers including the cortex.

Hyphae:

Long filamentous structures that make up fungi, including those in lichens.

Algal Layer: A layer within the thallus where algae or cyanobacteria reside and perform photosynthesis.