Beech, birch, horse chestnut, oak, poplar.
Other broad-leaved tree species.
Found across the entire structure of the standing tree and persists on fallen trees.
Annual. Gilled abundantly. Often occurs in clusters. Sometimes with a whitish stem. Variable in appearance. Individually can develop to a fair size. Upper surface may be white, grey (many shades), brown, charcoal black, or blue-black and may or may not be wet. Gills always an off-white. Desiccates to a beige-brown – sometimes tinged – and shrivels. Whitish spore.
Pleurotus dryinus (usually larger, singular, and with a silvery felted upper surface).
Attributed often to a selective white rot of the wood but with the ability to simultaneously degrade lignin and cellulose. Potentially weakly parasitic though often saprobic. Widespread fruiting across the trunk or scaffold limbs can cause concern, as regards structural stability. Can be associated with physiological decline when present alongside fungi such as Chondrostereum purpureum.