Lichens

Lichen growing on a tree trunk. The Blue Mountains, Australia.
Lichen growing on a tree trunk. The Blue Mountains, Australia.
A lichen is not a single organism. It is actually symbiosis between different organisms - a fungus and either an alga or cyanobacterium. 
For an excellent explanation on lichens, click  here  to go to this website: https://www.anbg.gov.au/lichen/what-is-lichen.html
Lichen's growing in Victoria, Australia
Lichen growing in Victoria, Australia
Lichen growing on a tree trunk. The Blue Mountains, Australia.
Lichen growing on a tree trunk. The Blue Mountains, Australia.
Lichen's growing in Victoria, Australia
Lichen's growing in Victoria, Australia
Lichen's growing in Victoria, Australia
Lichen's growing in Victoria, Australia
Lichen's growing in Victoria, Australia. Green branches with black tips.
Lichen's growing in Victoria, Australia