. TMA Fungi

Gymnopilus junonius

(Fr.) P.D. Orton

A single large cap growing at the base of a beech monolith in Epping Forest, Essex.
Emerging from between buttresses on veteran beech on heavily compacted ground at Epping Forest, Essex
A quartet of caps developing upon fallen English oak in New England Wood, Essex
Single mature cap on birch wood in Hockley Woods, Essex
The veil that has begun to partially break

A single large cap growing at the base of a beech monolith in Epping Forest, Essex.
Emerging from between buttresses on veteran beech on heavily compacted ground at Epping Forest, Essex
A quartet of caps developing upon fallen English oak in New England Wood, Essex
Single mature cap on birch wood in Hockley Woods, Essex
The veil that has begun to partially break
The distinct stem ring beneath the cap.
An over-mature fruit body with fungivory damage on beech in Epping, UK.
Developing caps on oak in Rochford, UK.
Developing caps on oak in Rochford, UK.
Maturing caps on a partially-submerged willow at Hatfield Forest, UK.

Common name

Laughing Jack; spectacular rustgill

Often found on

Deciduous broadleaved species.

Sometimes found on

conifers (particularly pine).

Location

Found at the base and along the main stem of the host tree – including from within cavities. Often more abundant on dead stems and stumps.

Description

Annual cap. Soft and fleshy. Can individually become quite large. Usually growing singularly or in groups of 2-5. Cap is a densely-striated golden orange with a yellowish ‘background’. Stem (stipe) is a light golden orange-yellow and partially ringed (veil breaks early on that covers gills). Gills are rust brown – coloured so by spore release.

Confused with

Armillaria sp. (white spore); Gymnopilus penetrans (more common on conifers – smaller); Pholiota aurivella (slightly scaled cap).

Significance

Attributed to a selective white rot of the wood. Generally considered saprotrophic though may potentially act as a parasite. Indicative of existing decay and dysfunction, on living trees – particularly indicative of root damage and basal decay, when found at and around the base of the host tree. Fructifications that encircle the stem base and / or along lengths of the stem may suggest physiological dysfunction and decay as caused by other wood-decay fungi.