English: Black witch's butter (Exidia glandulosa) One of the jelly fungi that are to be found on dead wood, in this case a rotten oak branch. A yellow form, Tremella mesenterica, goes by the name of Witch's butter, more understandably, but in fact the texture of these fungi is nothing like butter, being gelatinous - more so in wet weather than in dry when it shrivels and turns hard.

It is often described as having a warty surface (slightly visible here); this is caused by another fungus, Heteromycophaga glandulosae, which is parasitic upon this one: "Big fleas have little fleas...etc"!

Found in the damp woodlands of the Gwaun Valley.