Armillaria mellea, commonly known as honey fungus, is a type of mushroom found in forests and woodlands around the world. It typically grows on decaying wood and can be identified by its yellow-brown cap and white gills. This fungus is known for its ability to form large underground networks, which can spread over vast areas. Honey fungus is both a decomposer and a parasite, often attacking trees and shrubs, leading to their decline. While it plays a crucial role in breaking down organic matter, it can also cause significant damage to forests and gardens. Some species of Armillaria are edible, but caution is advised due to potential confusion with toxic look-alikes.