Armillaria (Fr.) Staude
(honey fungi)

An aggregate of species some of which are thought to be serious parasites which cause the death of their host tree while others are saprobic or even mycorrhizal species. The component species require culturing to distinguish.

Confirmation of the common Honey Fungus, Armillaria mellea, requires microscopic examination to check that there are no clamp connections at the base of the basidia. Congo Red in dilute ammonia is a suitable mountant. Place a tiny fragment of gill in the Congo Red, apply the cover slip and gently press with the end of a pencil. Leave for a few minutes to stain and soften, then, ideally, run in water (or dilute ammonia) before squashing again, harder this time, until the tissue breaks up and the basidia separate. (Take care as splashes of Congo Red will permanently stain clothing.) Examine under at least x40 objective.