Exidia thuretiana - White Brain Fungus

Taxonomy

Phylum: Basidiomycota

Class: Tremellomycetes

Order: Auriculariales

Exidia thuretiana is a relatively rare species of jelly fungus; it appears on rotting hardwood, and particularly beech. In dry weather this fungus shrinks and becomes quite hard. You will need wet weather to find this fungus: during dry spells it shrivels up almost completely to leave just a transparent rubbery patch on the host wood.

Autumn and winter are the best times to look for this species (syn. Exidia alba) which is inedible.

Identification Guide

Size	Individual fruit bodies grown to between 0.2 and 1cm across.
Description	Pure white when wet, drying to almost invisible, the fruiting bodies are cushion shaped, becoming contorted with age and fusing with neighbouring fruiting bodies to form a large mass severalcm across.
Spores	White.
Odour/taste	Not distinctive.
Habitat	Mainly on dead and decaying hardwood, particularly beech.
Season	Late autumn and early winter.
Occurrence	Infrequent or rare in most areas.
Similar species	Tremella mesenterica is yellow and has a brain-like structure.

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.