"Lichens are plants"
Lichen is a result of coexistence of two organisms: a fungus and an algae. Lichen tissue is visible as a mushroom tissue and relying on solid ground. In living tissue visible of the lichens lives the algae, which sustains the photosynthesis and can produce nutrients. Parasitic fungus lives besides algae. Therefore, the fungus can absorb water. In this perfectly balanced symbiosis, lichen can survive in environments where no other creature can develop. But after the first lichens are established in one location are followed by other creatures.