friendship mushroom

friendship mushroom (Armillaria tabescens)
Photo © Hank Guarisco

FEATURES
The friendship mushroom’s fruiting body is solid. Its cap and stem are not easily separated. The cap is tan to yellow and about one to two and one-third inches wide at maturity. Scales may be present on the top of the cap when it is fresh. The stem is light gray to light brown and about two to three inches long. The spores are smooth and white, and the spore print is white. The gills are broadly attached to the stem. There is no ring on the stalk and that is one trait that separates this species from the very similar honey mushroom (Armillaria mellea) that does have a ring on the stalk.

BEHAVIORS
The mycelium of this species is bioluminescent. It grows on tree roots. The fruiting bodies arise in clusters and may not seem to be growing from wood, but there will be tree roots under them in the soil when they appear, usually in late summer and early fall, especially after abundant rainfall. Friendship mushroom causes a root-rot disease that can kill trees. It tends to invade trees when they are stressed due to limited water or through a wound. They are more likely to attack fruit trees and ornamental trees than other tree species.

​Kingdom: Fungi
Phylum: Basidiomycota
Class: Agaricomycetes
Order: Agaricales
Family: Physalacriaceae