Lichens

These amazing little plants if that's the right word grow on some sand stones in my front garden.
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From the web
What is a lichen?

Leafy lichens
Leafy form of lichens

A lichen consists of 2 or more partners that live together symbiotically, with both of them benefiting from the alliance. One partner is a fungus. The other is either an alga (usually a green alga) or a cyanobacterium, which is sometimes called a blue-green alga although it is more closely related to bacteria than algae.

The alga or cyanobacterium is able to use sunlight to produce essential nutrients by photosynthesis that feed both partners. The fungus creates a body, called a thallus, in which they both live. The fungus also produces chemical compounds that may act as sunscreen to protect the photosynthetic partner.

Shrubby lichens
Shrubby form of lichens

There are about 30,000 species of lichen worldwide, and they come in a dazzling variety of shapes and colours. Some are almost invisible to the naked eye and grow as a crust on rocks, trees or soil. Others are called beard lichens and these can be bushy or trailing, sometimes growing up to three metres in length, and others are lobed and leaf-like. Colours range from dull grey-browns to brilliant yellows and bright orangey reds.