What is the common name for Armillaria sp.?

The common name for Armillaria sp. is indeed "Oak root fungus." This name reflects its association with oak trees, where it commonly causes root rot, leading to significant damage. Armillaria is a genus of fungi known for their ability to decay wood and some plants, primarily through colonizing the roots and lower trunk areas.

The term "oak root fungus" is particularly appropriate as it highlights a specific interaction with oak trees, indicating the host preference that this pathogen exhibits. Understanding its common name and its relationship to its host is essential for identifying the disease it causes and selecting effective management strategies.

The other choices pertain to different pathogens or diseases: "root rot" is a general term that may refer to various fungi affecting plant roots; "white rust" refers to a disease caused by a different group of fungi, specifically in the genus Albugo; "Fusarium wilt" is associated with pathogens in the Fusarium genus that cause wilting and decay in various plants. Each of these terms represents distinct diseases or fungi, making "oak root fungus" the precise and appropriate common name for Armillaria sp.