Tremella mesenterica (common names include the yellow brain, the golden jelly fungus, the yellow trembler, and witches' butter[1]) is a common jelly fungus in the family Tremellaceae of the Agaricomycotina. It is most frequently found on dead but attached and on recently fallen branches, especially of angiosperms, as a parasite of wood decay fungi in the genus Peniophora. The gelatinous, orange-yellow fruit body of the fungus, which can grow up to 7.5 cm (3.0 in) diameter, has a convoluted or lobed surface that is greasy or slimy when damp. It grows in crevices in bark, appearing during rainy weather. Within a few days after rain it dries into a thin film or shriveled mass capable of reviving after subsequent rain. This fungus occurs widely in broadleaf and mixed forests and is widely distributed in temperate and tropical regions that include Africa, Asia, Australia, Europe, North and South America. Although considered bland and flavorless, the fungus is edible. Tremella mesenterica produces carbohydrates that are attracting research interest because of their various biological activities.
- ^ Alternatively spelled witch's or witches