Spectacular Rustgill (Gymnopilus Junonius) Identification

Spectacular Rustgill / Summer / Autumn / Winter / Inedible

Scientific Name

Gymnopilus Junonius

Common Names

Spectacular Rustgill, Laughing Gym, Laughing Jim.




They are saprotrophic and are most often found on the stumps of deciduous trees, they do occasionally appear on coniferous stumps.


A large and fairly common mushroom with quite a long season.

Identifying Features:


Convex when young with an in rolled margin they flatten out with age but retain a slight central umbo. They are orange/yellow to brown in colour. The caps are covered with very fine orange coloured radial fibres.

Agnes Monkelbaan, CC BY-SA 4.0 <https://creativecommons.org/licenses/by-sa/4.0>, via Wikimedia Commons


Their stems are pretty stout and robust tending to get more bulbous towards the base. They are roughly the same colour as the caps. When the fruit bodies are young they have a cortina protecting the gills, as this breaks away it leaves a faint ring on the stem which will darken as it catches some of the spores.

Bernard Spragg. NZ from Christchurch, New Zealand, Public domain, via Wikimedia Commons


The gills are crowded and adnate, yellowish when young, the rust coloured spores darken the gills as they age.

Debivort, CC BY-SA 3.0 , via Wikimedia Commons


Slightly fruity.


Rusty, orange to brown.

Known hazards

Several mycologists have found that specimens from various parts of the world contain toxins, including the hallucinogens psilocybin and psilobin. The common name Laughing Jim (or Gym) has been given to this mushroom because of its hallucinogenic properties.

Bernard Spragg. NZ from Christchurch, New Zealand, Public domain, via Wikimedia Commons

Potential lookalikes

The Common Rustgill (Gymnopilus Penetrans) can look similar but this lacks the ring on the stem.

The Golden Bootleg (Phaeolepiota Aurea) can also look similar but this is a very rare mushroom and it has a yellowish spore print.

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