The convex or flattened cap has a shallow umbo and can either be minutely scaly or smooth.  The colour is red-brown to yellowy-brown, with a darker centre and paler, radially furrowed edge (like a piecrust). It is sticky when wet. The gills are emarginate and pale yellow, often with brown spots, and the flesh is yellow.   The stipe is the same colour as cap, and is fibrillose. 

Most other red-brown Tricholoma have pale or white gills, sometimes with brown spots; other species of yellow-brown Tricholoma have yellow gills.

• pale yellowish gills
• 'piecrust' edge to red-brown cap
• associated with birch

Photograph from top down and in side view, and from underneath to show gills and full length of stipe; note habitat and substrate

Usually under birch in boggy areas; occasonally conifers

Common and widespread (Kibby, Vol.2 (2020)

Status in Leicestershire and Rutland not known.

https://www.first-nature.com/fungi/tricholoma-fulvum.php