Does anybody know what this is, please?

[nobby]

Seen growing from a crevice in a sandstone block wall by a busy B road.

[Jaded]

Boris Johnson buggering the country?

[PaulF]

Looks like you’re being mooned by a gnome.

[Poacher]

Lithops?

[nobby]

Lithops?

Interesting thought.
Something along those lines but the South African connection is a long way from the West Midlands of England.
It is a fine piece of fungus (if it is funghus) for a place that cannot be very rich in nutrients.

Thanks for pointing to Lithops. Very interesting.

[ElyDave]

King Alfred's cakes, daldinia concentrica?

Possibly a young one, St Ray of Mears uses them as fire lighter when ripe. I'm not sure if they start light and go dark, or I'm just talking out of my arse here.

[nobby]

King Alfred's cakes, daldinia concentrica?

Possibly a young one, St Ray of Mears uses them as fire lighter when ripe. I'm not sure if they start light and go dark, or I'm just talking out of my arse here.

That looks like the answer! Thank you

It looks as though there are two types: a black one and a brown one. The first is good for tinder.
No sign of wood for it to grow on at this site though.

[ElyDave]

that's why i wasn't sure either

[nobby]

It's probably an urban chancer variant. My favourite kind of wildlife.