What notable feature of oak root fungus is identified along infected roots?

The notable feature of oak root fungus, particularly species such as Armillaria mellea, is the presence of shoelace-like rhizomorphs that can be found along infected roots. Rhizomorphs are specialized structures that function similarly to roots, allowing the fungus to transport nutrients and water. They typically have a smooth, shiny appearance and can often be seen growing both on the surface of the soil and along the infected roots of trees.

Identifying these rhizomorphs is critical in diagnosing oak root fungus, as their presence indicates that the fungus has a widespread and established presence in the area. This can signal potential management concerns for the health of the tree and adjacent plants, as oak root fungus can lead to significant root decay and ultimately tree mortality.