Abstract pattern of colourful lichens on a rock. Lichens or lichens are able to survive in extreme locations. Several species together form colourful patterns. A lichen is a coexistence of a fungus and an alga. This combination allows it to grow on rocks. Lichens grow abundantly on rocks in a humid environment and with clean air. In the mountains, conditions are favourable and you can find the most beautiful combinations. Like this photo taken in Austria, high in the Alps.