They were situated in leaf litter at the edges of the path.

They were up to about 160mm tall and a little less than 60mm across cap size.

The caps were mainly a cream colour, range-brown at the bumpy apex, fading to grey and finally black at the edges.

The edges were wavy and a little striated.

The stems were dark cream and less than 5mm across and the gills were grey, turning to black, and very close.

I found some more on Day 2 (24 September 2022):

[photos]

Day 3 – 01 October 2022:

And on Day 4 (08 October 2022) I found a singular one in tall grass.

I later found them in small groups throughout the fen.

These had white, motly caps, with a yellow-ish apex. The stems were thin and white, almost transparent, with grey gills.

Later with darker ruddy caps [ probably immature ] in shorter grass on soil in the open.