Gymnopilus decipiens

Taxonomy

Phylum: Basidiomycota

Class: Agaricomycetes

Order: Agaricales

This small and uncommon rustgill is found mainly on burnt wood and forest fire sites. There are many other very similar rustgills worldwide, and identification to species level is very difficult, requiring microscopic examination of spores and other features.

The easiest of the rustgills to identify is Gymnopilus junonius, the Spectacular Rustgill, which often grows on the trunks of ailing trees; it is the only Gymnopilus with a persistent stem ring.

If we were pressed to create a common name for this rather uncommon mushroom, it would be the Forest Fire Rustgill. As many of the Gymnopilus fungi contain the toxin psilobin, it is advisable to treat Gymnopilus decipiens and the many other small rustgills as poisonous mushrooms.

Identification guide

Cap	1 to 3cm across; convex, flattening; scaly or fibrillose; orange.
Gills	Adnate; fairly distant; yellow, turning reddish-brown, often with rusty-brown spots.
Stem	1 to 2cm long and 3 to 5mm in dia.; light brown, lower half covered in white fibres.
Spore print	Rusty brown.
Odour/taste	Odour not significant; taste bitter.
Habitat	On burned wood and sites of forest fires.
Season	June to November.
Occurrence	Infrequent.
Similar species	Gymnopilus junonius is larger and retains a stem ring; it occurs in woodland habitat, but unlike Gymnopilus decipiens it is seen more often on hardwood stumps and ailing trees, and not normally on burnt wood. Phaeolepiota aurea is a rare mushroom with a granulase cap and lower stem; its spores are light yellow-brown.

Reference Sources

Fascinated by Fungi, Pat O'Reilly 2011.

Dictionary of the Fungi; Paul M. Kirk, Paul F. Cannon, David W. Minter and J. A. Stalpers; CABI, 2008

Taxonomic history and synonym information on these pages is drawn from many sources but in particular from the British Mycological Society's GB Checklist of Fungi and (for basidiomycetes) on Kew's Checklist of the British & Irish Basidiomycota.