Lichens growing on rocks are called

Options

A. corticolous
B. coprophilous
C. terricolous
D. saxicolous

Answer

To answer the question "Lichens growing on rocks are called," we can follow these steps:

### Step-by-Step Solution:

1. **Understand what lichens are**: Lichens are a symbiotic association between fungi and algae. The algae can perform photosynthesis, while the fungi provide a protective environment for the algae.

2. **Identify the classification of lichens**: Lichens are classified based on the substrate or surface on which the fungal partner grows. This classification helps in identifying the specific type of lichen.

3. **Review the options given**: The options provided are:
- Corticollis
- Coprophilus
- Terricollis
- Saxicollis

4. **Analyze each option**:
- **Corticollis**: This type of lichen grows on the bark of trees.
- **Coprophilus**: This type of lichen grows on animal dung.
- **Terricollis**: This type of lichen grows on soil, particularly arid soil.
- **Saxicollis**: This type of lichen grows on rocks.

5. **Select the correct answer**: Based on the analysis, the type of lichen that grows on rocks is called **saxicollis**.

### Final Answer:
Lichens growing on rocks are called **saxicollis**.

---