The cap is an orange-brown colour and can be sticky when wet, while the stem is a dull yellow colour and the gills, which are yellowish develop rust-brown spots with age. Spore print rusty orange-brown, spores ellipsoidal, 7-9 x 4-5.5µm, covered in small warts.

Scaly Rustgill G sapineus, is very similar, on conifers but has rarely been recorded

Photograph from top down, in side-view, and underneath to show gills; note habitat and substrate,

On fallen wood debris of conifers and deciduous species, especially Birch.

Found from late spring to late autumn

Fairly common and widespread in Britain.

Fairly common in Leicestershire and Rutland.

https://www.first-nature.com/fungi/gymnopilus-penetrans.php