Armillariella mellea, commonly known as honey fungus, is a parasitic fungus that attacks trees, shrubs, and other woody plants. Synonyms for this species include Armillaria mellea, Armillariella tabescens, and Agaricus melleus. Honey fungi are among the most destructive plant pathogens, causing root rot that can lead to the death of the host plant. To identify honey fungus, look for clusters of mushrooms growing at the base of infected trees, as well as white, fan-shaped fungal mats under the bark. While difficult to control, preventing the fungus from spreading by removing infected trees and stumps can help protect nearby plants and prevent further damage.