Community find

Honey Fungus

Armillaria mellea

Group

gilled mushroom

Season

Late summer to late autumn, often after cooler, moist weather.

Habitat

Found in dense clusters on dead or living deciduous and coniferous wood, stumps, roots, or buried wood. It is a common parasite of trees, causing white rot.

Key characteristics

Caps are typically 2-15 cm in diameter, convex to flat, often with a central umbo. Color varies from honey-yellow to yellowish-brown, often darker towards the center. The cap surface is usually covered with persistent, fine, brownish to blackish scales, especially when young. Gills are whitish to yellowish, becoming somewhat dingy or spotted with age, adnate to decurrent. Stems are 5-20 cm long and 1-3 cm thick, fibrous, often tapering slightly towards the base or slightly swollen. They are typically honey-colored or brownish and feature a prominent, skirt-like, white to yellowish ring (annulus) which may have a yellowish, woolly edge.

Look-alikes

Several other Armillaria species (e.g., Armillaria tabescens, Armillaria gallica) can look similar. Galerina marginata (Deadly Galerina) is a deadly toxic species that can sometimes be mistaken for honey fungus, especially when growing on wood; however, Galerina marginata has brown spores and lacks a prominent ring and scales on the cap. Pholiota species also bear some resemblance but typically have rusty brown spore prints and usually lack the distinctive ring of Armillaria mellea.

Ecological role

Functions as a parasitic fungus on living trees, causing root disease and white rot in wood, eventually leading to the death of the host tree. It also acts as a saprophyte, decomposing dead wood and returning nutrients to the ecosystem. It forms extensive underground mycelial networks (rhizomorphs) which aid in nutrient cycling and can spread the fungus to new hosts.