brown cap and white, hollow stem.
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.
Watch it as it ages, Psathyrella hydrophila, quite common in Britain, looks similar, the gills initially pale brown turn chestnut as they get older, and the stem is white and snaps easily.
If it is Psilocybe, be careful, some species are hallucinogenic/toxic. Though the stems on this are said to be fairly tough. :)
Lat/Lng: 50.4951, -4.2242
OS grid ref: SX423685