Some type of bracket fungi attached to a rotting willow tree.
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.
Looks a bit olive oysterling to me.
It's the colour more than anything that made me think of Panellus serotinus.
Lat/Lng: 50.71913, -3.53305
OS grid ref: SX918921