Lichen

Description:

Lichens sometimes composite organisms consisting of a symbiotic organism composed of a fungus (the mycobiont) with a photosynthetic partner (the photobiont or phycobiont), usually either a green alga (commonly Trebouxia) or cyanobacterium (commonly Nostoc). Lichens occur in some of the most extreme environments on Earth—arctic tundra, hot deserts, rocky coasts, and toxic slag heaps. They are also abundant as epiphytes on leaves and branches in rain forests and temperate woodland, on bare rock, including walls and gravestones, and on exposed soil surfaces (e.g., Collema) in otherwise mesic habitats.

Habitat:

Lichens have specific requirements for their habitats. Although they can occur on a variety of substrates, each substrate must have the individual components in the right amounts that growing lichen needs. Lichens are remarkable in that they can tolerate the most extreme environments, thus they can live in hot dry places as well as arctic conditions and the wettest of rain forest. Although they can tolerate salt spry and immersion in water they are not aquatic. For this reason they are nature's pioneers. Been first to colonise the most inhospitable places from there they begin the slow process of creating the foundation for other habitation.

Notes:

This Lichen in the picture was found growing on a tree in the park. There wasn't a lot of it but sooner it would of started to grow more and more the tree.