Black lirellae on side of sycamore trunk. No definite thallus. Possibly Opegrapha atra.
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.
The lirellae don't have the right appearance for Opegrapha atra - compare with this photo on British Lichens:
There are a number of small non-lichenised fungi which can look similar, couple of examples below:
Hysterium angustatum: http://www.irishlichens.ie/pages-fungi/f-77.html
Ascodichaena rugosa: http://www.irishlichens.ie/pages-fungi/f-76.html
Many thanks for the fungus information and links. Looks like the Hysterium angustatum. Very grateful.
Glad to have been of help but I should have added that you need spore details for identification as there are a number of similar species
Just to say that I agree with Jenny's posts here. I have been caught out myself (for a short time at least) by H. angustatum.
Lat/Lng: 52.1609, 0.0085
OS grid ref: TL374533