Growing on dead birch trunk
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.
I agree that this MIGHT be G. marginata, though the ring looks a bit too substantial... MushroomExpert.com says "when young with a whitish partial veil covering the gills--later with a ring that is often fragile and collapsed, or with a ring zone (though specimens are sometimes found in which all evidence of the partial veil has disappeared); the ring white at first but soon dusted with rusty brown spores". The rings in the photos are, on the other hand, quite magnificent!
Lat/Lng: 52.1781, -0.153
OS grid ref: TL263549