As we start the 2022 fungi recording year there are three species that people often confuse when it comes to their common names. Witches' Butter (Exidia glandulosa), Warlock's Butter (Exidia nigricans) and Yellow Brain (Tremella mesenterica). Whilst they are similar in all being jelly like to the touch and occurring on wood, they are all very different in reality.
Warlock's Butter is black and hugs the wood, often forming quite extensive patches. It is found on a range of wood species but seems to like Beech the most.
Witches' Butter differs from the above species in usually being found on Oak and extruding from the wood rather than hugging it, producing individual growths rather than patches.
Yellow Brain is very different to the previous two species, it is yellow, like butter, which is why people often mistakenly call this Witches' Butter. The reason the two Exidia species above are butters are because they butter like in texture, but dark from the magic of Warlocks and Witches.
Yellow Brain is more brain like, so it is a brain not a butter. Simple? Yellow Brain is a common species and it is parasitic on other Peniophora species of fungi - a crust like fungi you can see in this image. There is a very close look-a-like to Yellow Brain called Tremella aurantia, which parasitises Hairy Curtain Crust (Stereum hirsutum).
All three seem to be fruiting at the moment so it is well worth getting out into the woodlands and seeing if you can find any.
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