Armillaria Root Rot: Identifying Characteristics
Identifying the injury:
Trees have thin crowns, may have wilting branches, dieback and loss of vigor; death. Roots are often rotted and poorly developed causing trees to lean.
Identifying the fungus:
The fruiting bodies (mushrooms) are yellow-brown and produced in clusters near the base or on roots of affected trees in cooler, wetter weather. Rhizomorphs may be seen on affected roots and stumps or in soil – look for black "shoestring-like" masses on dead wood. Fungal tissue (mycelium) is white and occurs under the bark. It sometimes glows in the dark (exhibiting bioluminescence).
Susceptible trees:
Many species – oaks and sweetgums are common hosts in Florida. Stressed trees are most likely to be affected.