[1] Peniophora quercina produces resupinate fruit bodies that vary in appearance depending on whether they are wet or dry.

[5] When fresh, the surface is reminiscent of jelly or wax, and can be smooth or warty, varying in colour from a dull blue to lilac.

Initially, they are firmly attached to the wood on which they are growing, but as they dry, the edges roll inwards[4] and reveal the dark brown or black underside.

[5] The dry specimens have a crusty and slightly fissured surface, and, in colour, are a bright pink or grey, tinted with lilac.

[2] The species has hyaline cystidia with thick cell walls, which are "heavily encrusted with crystalline material".

However, the edges of the fruit body are highlighted in a dark black, and the species favours ash, as opposed to oak.

[8] Peniophora quercina typically grows upon dead wood, which can be attached to the tree or fallen,[4] where it causes white rot.

[9] Another study found that the species actively colonised partially living branches, causing white rot.