Myxarium nucleatum (Crystal brain) Exidia nucleata
Species: M. nucleatum
Binomial name: Myxarium nucleatum
Synonyms: Exidia nucleata, Tremella nucleata, Naematelia nucleata, Tremella gemmata, Naematelia gemmata, Exidia gemmata, Naematelia atrata, Myxarium atratum, Exidia alboglobosa, Exidia tremelloides, Myxarium tremelloides, Myxarium hyalinum.
Common names: Crystal brain, Granular jelly roll.
Myxarium nucleatum is a translucent, white, jelly fungus in the family Hyaloriaceae. The sporocarps (fruit bodies) are watery white and gelatinous whose principal field mark is the presence of small, white, mineral inclusions (up to 0.5 mm in diameter) within the flesh of the fruiting body. It is a common fungi, typically growing as irregular masses on decaying deciduous wood. It can occur in extensive patches, becoming convoluted and brain-like in shape, hence its common name 'Crystal brain'. Initially it is colourless or whitish, becoming pinkish to a reddish-brown or a vinaceous-brown.
Myxarium nucleatum typically fruits in autumn and winter. It is widely distributed in Europe, North, Central and South America and New Zealand.
The species is still frequently referred to the genus Exidia, but molecular research, based on cladistic analysis of DNA sequences, has indicated that it belongs in a Myxarium clade that is quite separate from the Exidia clade.