New Zealand Lichen

Lichen are the combination of fungus and algae living in a symbiotic relationship with the fungus surrounding the algae cells. The body (thallus) of lichen is however different from either. Not only does the fungus trap and retain water for the algae it provides shelter. The algae in return has photosynthetic ability to provide the fungi with nutrient. Together as lichen they can exist in extreme conditions.