Armillaria is a genus of fungi commonly known as honey mushrooms. These mushrooms are found in forests and woodlands, often growing on decaying wood or living trees. They play a crucial role in the ecosystem by breaking down organic matter and recycling nutrients back into the soil. Some species of Armillaria are known for their ability to cause root rot in trees, making them significant in forestry and agriculture. They can spread through underground networks of mycelium, allowing them to infect large areas. Despite their potential to harm trees, honey mushrooms are also edible and enjoyed by many for their flavor.