Growing on and mostly between bricks on a low wall, in a shady spot.
Caution: Do NOT use iSpot to identify fungi to eat!
Some fungi are very poisonous so a mistaken ID could have serious consequences.
No interactions present.
A lichen ménage à trois - http://science.sciencemag.org/content/353/6297/337
Some say it's time to throw the textbook understanding of lichens out the window.
"Now there will be more chaos, more confusion in lichenology ,...."
Lat/Lng: 51.49313, -0.01522
OS grid ref: TQ378789
Low wall below the trees at the link to Undine Road.