Does Lichen go Here, or in Fungus?

[PeteTheBloke]

Here's some lichen I see a lot of in Donegal.



Anyone recognise it?

[RobSutton]

The very green one right in the middle looks like Rhizocarpon geographicum. I'm not sure whether it comes in brown as well so the rest could either be something else or the same but a different colour. Not much help to you there I'm afraid.

[PeteTheBloke]

Thanks Rob

Just googled Rhizocarpon geographicum and it looks about right. The other colonies look different. It's interesting the way they appear to be competing, like growths on an agar plate. I know less about lichen than almost any other branch of natural history; I wonder if there are 2, or even 3 or 4 types (would species be the correct word??) fighting for space here.