The caps are variable in colour from honey-coloured to brownish-yellow, sometimes with a greenish tint, through red-brown to a darker brown.  The caps have small scattered darker squamules, especially in the centre.  The gills are creamy or yellowish, sometimes with rusty spots.  There is a persistent yellowish ring.

A serious parasite of many species of trees and shrubs, often responsible for the death of specimen trees, fruit trees, hedgrow shrubs etc. in parks and gardens. Long black 'bootlaces' or rhizomorphs can be found under the bark of dead and dying trees.

other Armillaria species: Dark Honey fungus Armillaria ostoyae and Bulbous Honey fungus  Armillaria gallica.  (In the past these have been considered to be varieties of A mellea, but are now treated as separate species)

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

On or up against broad-leaf and conifer trees; also occurring on stumps and roots, and occasionally on fallen branches.

July to November

Common and widespread in Britain.

Very common in Leicestershire and Rutland.

https://www.first-nature.com/fungi/armillaria-mellea.php