The cap is bell-shaped. flattening to convex as it matures.  Colour varies depending on whether it is wet or dry, from dark brown to pale beige or cream when dry; often with a paler centre.  Gills pale brown, maturing to mottled dark brown.   Spores dark brown with rough surface.

Mottlegills, especially Turf Mottlegill (Panaeolus fimicola)

microscope

Photograph from top down, in side-view and underneath to show gills; note habitat and substrate. This can be a difficult fungus to identify and we recommend that spores are examined, or that it is verified by an expert from a specimen before submission to NatureSpot.

Lawns, verges and mown grasslands

April to December.

Common and widespread throughout Britain.

Fairly frequent in Leicestershire and Rutland.

https://www.first-nature.com/fungi/panaeolina-foenisecii.php

[On the NBN under Order Agaricales and not assigned to a Family; but included here along with other mottlegills].