English: Yellow Brain Fungus (Tremella mesenterica) This is one of the most frequently encountered of the Jelly Fungi. Shown here is a particularly large group which was about 15cm (6") high. Prolonged dry weather will make this fungus shrivel to a fraction of its normal size, but it returns to normal size when next moistened. This fungus is usually coloured as shown here, but it can also occur as forms that are colourless (or nearly so). [The latter more washed-out forms used to be considered another species, Tremella lutescens, but they are now generally thought merely to be colour variants rather than a different species. As a final twist, similar but colourless fungi could also be something entirely different, such as Exidia thuretiana (White Brain) or Exidia nucleata (Crystal Brain); it can be difficult to tell without microscopic examination.]