several whitish grey crustose lichen with black spores in centre. Each one has well demarcated boundaries.
No identification made yet.
No interactions present.
Not sure what it is but certainly a striking image! hopefully someone will come up with an ID.
It is a lovely picture. Wonder if it could be Porpidia tuberculosa. According to Lichens by Frank Dobson it is common on pebbles
Lat/Lng: 52.0, -0.9
OS grid ref: SP7840