Young caps are bright yellow, sticky and domed.  As they age they become flattened or parasol shapes, and fade to a greyish or brownish colour, sometimes retaining a yellow centre until mature. Gills yellow when fresh but becoming rusty brown as the spores ripen. Spore print brown, spores ellipsoidal, smooth.

In grassy places, especially where manured, and on compost etc.

Found from spring until autumn

Fairly common in much of Britain.

Fairly common in Leicestershire and Rutland.

https://www.first-nature.com/fungi/bolbitius-titubans.php