1. Lichens are dual organisms. Because, it is made up of two organisms, Algae and Fungi.
2. It is autophagous and self-sufficient.
3. It is heterozygous, flattened, monoecious and non-flowering.
4. The fungus forms the thallus structure and the algae are encased inside the structure.
5. It is grey, grey-green, white, yellow, fawn, green, red, pink or black in colour.
6. The algal member accounts for 5–10% of the mass of the lichen thallus.
7. They can range from tiny to several feet.
8. Lichens can grow in all environments of the world. Hence they are called Cosmopolitan plants.
9. They can be homomerous and heteromerous.
10. They have rhizines like rhizoids. Rhizine absorbs water.
11. Their reproductive function is usually controlled by fungi.
12. Lichens are highly sensitive to air pollution.
13. They reproduce in organ, asexual and sexual ways.
14. In sterile sterile media, lichens can grow where no organisms can grow.
15. It acts as a precursor to soil formation in hard rock.