-Spore print dotted purple-brown (seen on caps of older clustered specimens that have covered one another).
-Stem bright yellow to developing rusty brown stains from base upwards.
(https://www.mushroomexpert.com/hypholoma_fasciculare.html)

On fallen hazel branch; rotting due to Peniophora, of which T. mesenterica is parasitizing.

"Tremella aurantia is most easily distinguished by its host preference, attacking the common wood rotter, Stereum hirsutum, while Tremella mesenterica parasitizes species of Peniophora, a resupinate fungus. (www.mykoweb.com/CAF/species/Tremella_au"rantia.html)

-"Yellow Brain fungus grows on dead wood that has been attacked by wood-rotting fungi of the Peniophora genus. Very little or none of the Peniophora may be visible if Tremella mesenterica has fully colonised all of the infected surface of the wood, and so it may look as though Yellow Brain is feeding directly on the host wood." (https://www.first-nature.com/fungi/tremella-mesenterica.php)