Yellw-brown cap, shiny. White Gills and white, clear 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.
Why do you think it is R.decolorans rather than say R. ochroleuca or one of the other yellow Russulas? The colour reminds me more of R. ochroleuca which is why I might suggest that one but there are other possibilities too.
You could well be correct with R. ochroleuca, the colour is probably closer to the photo. At least we can agree on Russula.
Thanks for your comments,
Lat/Lng: 53.3, -1.6
OS grid ref: SK2880