Inonotus dryadeus is a parasitic
saprobic fungus, with spores entering wounds on broadleaf trees (predominantly oak, although sometimes maple, elm and chestnut). The fungus is primarily a root decay fungus, rotting the below−ground parts of roots. Detection is often difficult if the conks have not developed. The fruiting conks appear close to the ground on the trunk, thickly attached, and either singly or in groups. It has been observed in North America and temperate northern Europe, where it is described as widespread but locally common. Fruiting occurs in summer and autumn, but fruit bodies may overwinter and persist for several years, eventually turning black and cracked. Presence of a fruit body may indicate that the
mycelium has penetrated and weakened the
root crown of the tree. ==References==