
TreeOleaceae
Fraxinus excelsior

So closely associated with dead Ash wood that it is practically diagnostic of the species. The relationship carries conservation urgency, Ash Dieback (Hymenoscyphus fraxineus) threatens both the host tree and this fungus across Europe.

Also abundant on ash bark, particularly in moist western woodlands.

Ash is a frequent mistletoe host in western European woodlands, particularly in Britain and France.