Phanerochaete chrysorhiza.

The Spreading yellow tooth fungus.
Basidiomycota > Polyporales > Phanerochaetaceae.

There are many synonyms including Hydnum chryscomum, H. fragilissimum, Hydnophlebia chrysorhiza,
    Mycoacia fragilissima, M. chrysorhiza, Oxydontia chrysorhiza, O. fragilissima and Odontia crocea.

A crust fungus that can be easily removed from the wood substrate.
They cause a white rot.

Individual crusts to 6 cm or more across.
There may be branching, orange rhizomorphs up to 20 cm long.

The crust is bright reddish-orange or orange-yellow.
The margin may be the same colour or whitish.
The growing margin has fine hairs or long, slender, hair-like processes or hyphae.

The spore bearing surface is the same colour as the crust.
It is covered with crowded conical, yellow to orange teeth, up to about 2 mm high with rounded tips.
(In some species the teeth are just very low bumps.)

Specimens are sometimes found with just a few scattered teeth or none at all.