Anyone know this? Black cap, white gills, on wood

Hi, and welcome to UK Fungi.

In your final two images, the cap appears have a faint umbo, and looks to be very faintly fibrillose/striate, having distinctly dark grey tones, with what I would describe as bluish tints.

The only wood inhabiting species that readily springs to mind with those particular macro characteristics is Willow Shield. – Pluteus salicinus.

However, The stem on your example seems to be much thicker than I would expect for that species (relative to cap diameter).

A spore print would be useful, (pale pink for P.salicinus), as it would enable you to include or exclude various genera, but I think this would be one which would definitely be needing microscopy to get anywhere near a confident species ID.

Regards,

Mike.

It does look like a Russula, especially the gills. It wwas growing very close to the ground, and the wood looks quite decomposed there, so I wouldn’t rule it out.

I recommend doing spore prints on glass. Then you can use a razor to scrape the spores together until you have a thicker mass. What looks white when in a thin layer might show a pinkish tinge (like Pluteus) or from pure white through cream to ochre for Russulas, depending on species.

Russula is a difficult genus and need to be keyed out properly. Even then…

Spore mass colour and taste especially. Smell occasionally useful.

Mycorrhizal host.

Extent of cap peeling